From 4afaff0cd58926e93f0d42fe9e30d77177e0b1b1 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 30 Jan 2020 13:42:22 -0800
Subject: [PATCH 01/38] Refactor helper and expose it

---
 .../client_wrapper/flutter_view_controller.cc |  3 +
 .../include/flutter/flutter_view_controller.h |  2 +
 shell/platform/windows/flutter_windows.cc     |  6 ++
 .../platform/windows/public/flutter_windows.h |  1 +
 shell/platform/windows/win32_dpi_helper.cc    | 67 +++++++++++++------
 shell/platform/windows/win32_dpi_helper.h     | 12 ++++
 shell/platform/windows/win32_window.cc        |  7 ++
 shell/platform/windows/window_state.h         |  3 +
 8 files changed, 80 insertions(+), 21 deletions(-)

diff --git a/shell/platform/windows/client_wrapper/flutter_view_controller.cc b/shell/platform/windows/client_wrapper/flutter_view_controller.cc
index 92a853862d77c..1d95c4c5234e7 100644
--- a/shell/platform/windows/client_wrapper/flutter_view_controller.cc
+++ b/shell/platform/windows/client_wrapper/flutter_view_controller.cc
@@ -57,4 +57,7 @@ FlutterDesktopPluginRegistrarRef FlutterViewController::GetRegistrarForPlugin(
   return FlutterDesktopGetPluginRegistrar(controller_, plugin_name.c_str());
 }
 
+  UINT FlutterViewController::GetViewDpi() {
+    return FlutterDesktopViewGetDpiForView(controller_, view()->GetNativeWindow());
+  }
 }  // namespace flutter
diff --git a/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h b/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
index c72b285227240..f8a278cbdb9b6 100644
--- a/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
+++ b/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
@@ -51,6 +51,8 @@ class FlutterViewController : public PluginRegistry {
   FlutterViewController& operator=(FlutterViewController const&) = delete;
 
   FlutterView* view() { return view_.get(); }
+  UINT GetViewDpi();
+
 
   // Processes any pending events in the Flutter engine, and returns the
   // nanosecond delay until the next scheduled event (or  max, if none).
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index 67ab22a5c937f..a2e4af2b8bb5f 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -19,6 +19,7 @@
 #include "flutter/shell/platform/windows/keyboard_hook_handler.h"
 #include "flutter/shell/platform/windows/platform_handler.h"
 #include "flutter/shell/platform/windows/text_input_plugin.h"
+#include "flutter/shell/platform/windows/win32_dpi_helper.h"
 #include "flutter/shell/platform/windows/win32_flutter_window.h"
 #include "flutter/shell/platform/windows/win32_task_runner.h"
 #include "flutter/shell/platform/windows/window_state.h"
@@ -149,6 +150,7 @@ FlutterDesktopViewControllerRef FlutterDesktopCreateViewController(
   }
   state->view->SetState(engine_state->engine);
   state->engine_state = std::move(engine_state);
+  state->dpi_helper = std::make_unique<flutter::Win32DpiHelper>();
   return state;
 }
 
@@ -182,6 +184,10 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view) {
   return view->window->GetWindowHandle();
 }
 
+UINT FlutterDesktopViewGetDpiForView(FlutterDesktopViewControllerRef controller, HWND hwnd) {
+  return controller->dpi_helper->GetDpi(hwnd);
+}
+
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
                                                 const char* icu_data_path,
                                                 const char** arguments,
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index 66c8287ab16fa..61aabd1357f4f 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -76,6 +76,7 @@ FlutterDesktopProcessMessages(FlutterDesktopViewControllerRef controller);
 
 // Return backing HWND for manipulation in host application.
 FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
+FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForView(FlutterDesktopViewControllerRef controller, HWND hwnd);
 
 // Runs an instance of a headless Flutter engine.
 //
diff --git a/shell/platform/windows/win32_dpi_helper.cc b/shell/platform/windows/win32_dpi_helper.cc
index 40a79e72c31d9..7d8ce2b978ede 100644
--- a/shell/platform/windows/win32_dpi_helper.cc
+++ b/shell/platform/windows/win32_dpi_helper.cc
@@ -1,5 +1,6 @@
 #include "flutter/shell/platform/windows/win32_dpi_helper.h"
 
+#include <iostream>
 namespace flutter {
 
 namespace {
@@ -19,24 +20,6 @@ Win32DpiHelper::Win32DpiHelper() {
   if (user32_module_ == nullptr) {
     return;
   }
-
-  if (AssignProcAddress(user32_module_, "GetDpiForWindow",
-                        get_dpi_for_window_)) {
-    dpi_for_window_supported_ = true;
-    return;
-  }
-
-  shlib_module_ = LoadLibraryA("Shcore.dll");
-  if (shlib_module_ == nullptr) {
-    return;
-  }
-
-  if (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
-                        get_dpi_for_monitor_) &&
-      AssignProcAddress(user32_module_, "MonitorFromWindow",
-                        monitor_from_window_)) {
-    dpi_for_monitor_supported_ = true;
-  }
 }
 
 Win32DpiHelper::~Win32DpiHelper() {
@@ -48,20 +31,62 @@ Win32DpiHelper::~Win32DpiHelper() {
   }
 }
 
+BOOL Win32DpiHelper::IsDpiPerWindowSupportedForWindow(HWND hwnd) {
+  if (!dpi_for_window_api_loaded_) {
+    dpi_for_window_supported_ =
+        (AssignProcAddress(user32_module_, "GetDpiForWindow",
+                           get_dpi_for_window_) &&
+         AssignProcAddress(user32_module_, "GetWindowDpiAwarenessContext",
+                           get_window_dpi_awareness_context_) &&
+         AssignProcAddress(user32_module_, "AreDpiAwarenessContextsEqual",
+                           are_dpi_awareness_contexts_equal));
+    dpi_for_window_api_loaded_ = true;
+  }
+  if (!dpi_for_window_supported_) {
+    return false;
+  }
+
+  DPI_AWARENESS_CONTEXT context = get_window_dpi_awareness_context_(hwnd);
+  return are_dpi_awareness_contexts_equal(
+      context, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+}
+
+BOOL Win32DpiHelper::IsDpiPerMonitorSupported() {
+  if (!dpi_for_monitor_api_loaded_) {
+    shlib_module_ = LoadLibraryA("Shcore.dll");
+    if (shlib_module_ == nullptr) {
+      return false;
+    }
+    dpi_for_monitor_supported_ =
+        (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
+                           get_dpi_for_monitor_) &&
+         AssignProcAddress(user32_module_, "MonitorFromWindow",
+                           monitor_from_window_));
+    dpi_for_monitor_api_loaded_ = true;
+  }
+  return dpi_for_monitor_supported_;
+}
+
 UINT Win32DpiHelper::GetDpi(HWND hwnd) {
   // GetDpiForWindow returns the DPI for any awareness mode. If not available,
   // fallback to a per monitor, system, or default DPI.
-  if (dpi_for_window_supported_) {
+  if (hwnd != nullptr && IsDpiPerWindowSupportedForWindow(hwnd)) {
+    std::cerr << "v2\n";
     return get_dpi_for_window_(hwnd);
   }
 
-  if (dpi_for_monitor_supported_) {
-    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
+  if (IsDpiPerMonitorSupported()) {
+    std::cerr << "monitor\n";
+
+    DWORD monitor_flag =
+        hwnd == nullptr ? MONITOR_DEFAULTTOPRIMARY : MONITOR_DEFAULTTONEAREST;
+    HMONITOR monitor = monitor_from_window_(hwnd, monitor_flag);
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
         get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
     return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
   }
+  std::cerr << "system\n";
 
   HDC hdc = GetDC(hwnd);
   UINT dpi = GetDeviceCaps(hdc, LOGPIXELSX);
diff --git a/shell/platform/windows/win32_dpi_helper.h b/shell/platform/windows/win32_dpi_helper.h
index 6ded84836713f..63a1d357e4b29 100644
--- a/shell/platform/windows/win32_dpi_helper.h
+++ b/shell/platform/windows/win32_dpi_helper.h
@@ -23,21 +23,33 @@ class Win32DpiHelper {
   UINT GetDpi(HWND);
 
  private:
+ BOOL IsDpiPerWindowSupportedForWindow(HWND hwnd);
+ BOOL IsDpiPerMonitorSupported();
+
   using GetDpiForWindow_ = UINT __stdcall(HWND);
   using GetDpiForMonitor_ = HRESULT __stdcall(HMONITOR hmonitor,
                                               MONITOR_DPI_TYPE dpiType,
                                               UINT* dpiX,
                                               UINT* dpiY);
   using MonitorFromWindow_ = HMONITOR __stdcall(HWND hwnd, DWORD dwFlags);
+  using GetWindowDpiAwarenessContext_ =
+      DPI_AWARENESS_CONTEXT __stdcall(HWND hwnd);
+  using AreDpiAwarenessContextsEqual_ =
+      BOOL __stdcall(DPI_AWARENESS_CONTEXT dpiContextA,
+                     DPI_AWARENESS_CONTEXT dpiContextB);
 
   GetDpiForWindow_* get_dpi_for_window_ = nullptr;
   GetDpiForMonitor_* get_dpi_for_monitor_ = nullptr;
   MonitorFromWindow_* monitor_from_window_ = nullptr;
+  GetWindowDpiAwarenessContext_* get_window_dpi_awareness_context_ = nullptr;
+  AreDpiAwarenessContextsEqual_* are_dpi_awareness_contexts_equal = nullptr;
 
   HMODULE user32_module_ = nullptr;
   HMODULE shlib_module_ = nullptr;
   bool dpi_for_window_supported_ = false;
   bool dpi_for_monitor_supported_ = false;
+  bool dpi_for_window_api_loaded_ = false;
+  bool dpi_for_monitor_api_loaded_ = false;
 };
 
 }  // namespace flutter
diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index e499bfbd129f8..ccc9095a56c13 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -4,6 +4,8 @@
 
 #include "flutter/shell/platform/windows/win32_window.h"
 
+#include <iostream>
+
 namespace flutter {
 
 Win32Window::Win32Window() {}
@@ -75,6 +77,9 @@ LRESULT CALLBACK Win32Window::WndProc(HWND const window,
 
     auto that = static_cast<Win32Window*>(cs->lpCreateParams);
     that->current_dpi_ = that->dpi_helper_->GetDpi(window);
+    std::cerr << "Current dpi" << std::endl;
+    std::cerr << that->current_dpi_ << std::endl;
+
     that->window_handle_ = window;
   } else if (Win32Window* that = GetThisFromHandle(window)) {
     return that->MessageHandler(window, message, wparam, lparam);
@@ -268,6 +273,8 @@ Win32Window::HandleDpiChange(HWND hwnd,
     // hence call function to get DPI if needed.
     if (uDpi == 0) {
       uDpi = dpi_helper_->GetDpi(hwnd);
+       std::cerr << "New dpi" << std::endl;
+    std::cerr << uDpi << std::endl;
     }
     current_dpi_ = uDpi;
     window->OnDpiScale(uDpi);
diff --git a/shell/platform/windows/window_state.h b/shell/platform/windows/window_state.h
index 254ab46c2ead9..30bb39524f2bd 100644
--- a/shell/platform/windows/window_state.h
+++ b/shell/platform/windows/window_state.h
@@ -12,6 +12,7 @@
 #include "flutter/shell/platform/windows/keyboard_hook_handler.h"
 #include "flutter/shell/platform/windows/platform_handler.h"
 #include "flutter/shell/platform/windows/text_input_plugin.h"
+#include "flutter/shell/platform/windows/win32_dpi_helper.h"
 #include "flutter/shell/platform/windows/win32_task_runner.h"
 
 struct flutter::Win32FlutterWindow;
@@ -27,6 +28,8 @@ struct FlutterDesktopViewControllerState {
 
   // The window handle given to API clients.
   std::unique_ptr<FlutterDesktopView> view_wrapper;
+
+  std::unique_ptr<flutter::Win32DpiHelper> dpi_helper;
 };
 
 // Opaque reference for the native windows itself. This is separate from the

From f133955f2481f03408a95c0be6d66f9122cd57dc Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 30 Jan 2020 16:25:04 -0800
Subject: [PATCH 02/38] mostly works but with two helpers

---
 .../windows/client_wrapper/flutter_view_controller.cc        | 4 ----
 .../client_wrapper/include/flutter/flutter_view_controller.h | 2 --
 shell/platform/windows/flutter_windows.cc                    | 5 +++--
 shell/platform/windows/public/flutter_windows.h              | 3 ++-
 shell/platform/windows/win32_dpi_helper.cc                   | 4 +---
 5 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/shell/platform/windows/client_wrapper/flutter_view_controller.cc b/shell/platform/windows/client_wrapper/flutter_view_controller.cc
index 1d95c4c5234e7..296b13e805c47 100644
--- a/shell/platform/windows/client_wrapper/flutter_view_controller.cc
+++ b/shell/platform/windows/client_wrapper/flutter_view_controller.cc
@@ -56,8 +56,4 @@ FlutterDesktopPluginRegistrarRef FlutterViewController::GetRegistrarForPlugin(
   }
   return FlutterDesktopGetPluginRegistrar(controller_, plugin_name.c_str());
 }
-
-  UINT FlutterViewController::GetViewDpi() {
-    return FlutterDesktopViewGetDpiForView(controller_, view()->GetNativeWindow());
-  }
 }  // namespace flutter
diff --git a/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h b/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
index f8a278cbdb9b6..c72b285227240 100644
--- a/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
+++ b/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
@@ -51,8 +51,6 @@ class FlutterViewController : public PluginRegistry {
   FlutterViewController& operator=(FlutterViewController const&) = delete;
 
   FlutterView* view() { return view_.get(); }
-  UINT GetViewDpi();
-
 
   // Processes any pending events in the Flutter engine, and returns the
   // nanosecond delay until the next scheduled event (or  max, if none).
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index a2e4af2b8bb5f..da9dd9bc96032 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -184,8 +184,9 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view) {
   return view->window->GetWindowHandle();
 }
 
-UINT FlutterDesktopViewGetDpiForView(FlutterDesktopViewControllerRef controller, HWND hwnd) {
-  return controller->dpi_helper->GetDpi(hwnd);
+UINT FlutterDesktopViewGetDpiForView(HWND hwnd) {
+  static flutter::Win32DpiHelper* dpi_helper = new flutter::Win32DpiHelper();
+  return dpi_helper->GetDpi(hwnd);
 }
 
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index 61aabd1357f4f..958d7464acf53 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -76,7 +76,8 @@ FlutterDesktopProcessMessages(FlutterDesktopViewControllerRef controller);
 
 // Return backing HWND for manipulation in host application.
 FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
-FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForView(FlutterDesktopViewControllerRef controller, HWND hwnd);
+
+FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForView(HWND hwnd);
 
 // Runs an instance of a headless Flutter engine.
 //
diff --git a/shell/platform/windows/win32_dpi_helper.cc b/shell/platform/windows/win32_dpi_helper.cc
index 7d8ce2b978ede..9fef9de0fe7a7 100644
--- a/shell/platform/windows/win32_dpi_helper.cc
+++ b/shell/platform/windows/win32_dpi_helper.cc
@@ -78,9 +78,7 @@ UINT Win32DpiHelper::GetDpi(HWND hwnd) {
   if (IsDpiPerMonitorSupported()) {
     std::cerr << "monitor\n";
 
-    DWORD monitor_flag =
-        hwnd == nullptr ? MONITOR_DEFAULTTOPRIMARY : MONITOR_DEFAULTTONEAREST;
-    HMONITOR monitor = monitor_from_window_(hwnd, monitor_flag);
+    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
         get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);

From 098a89bb0b43def02bdb842392ed3108a1333648 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 11:25:21 -0800
Subject: [PATCH 03/38] Now with scaling

---
 ci/licenses_golden/licenses_flutter           |  4 +-
 shell/platform/windows/BUILD.gn               |  4 +-
 shell/platform/windows/flutter_windows.cc     | 11 ++-
 .../platform/windows/public/flutter_windows.h |  1 +
 shell/platform/windows/win32_dpi_helper.cc    | 94 -------------------
 shell/platform/windows/win32_dpi_helper.h     | 57 -----------
 shell/platform/windows/win32_window.cc        | 12 ++-
 shell/platform/windows/win32_window.h         |  6 --
 shell/platform/windows/window_state.h         |  3 -
 9 files changed, 19 insertions(+), 173 deletions(-)
 delete mode 100644 shell/platform/windows/win32_dpi_helper.cc
 delete mode 100644 shell/platform/windows/win32_dpi_helper.h

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 5080f5b095eaa..0fb09282b57c3 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1108,6 +1108,8 @@ FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flu
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/plugin_registrar_windows.h
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/plugin_registrar_windows_unittests.cc
+FILE: ../../../flutter/shell/platform/windows/dpi_utils.h
+FILE: ../../../flutter/shell/platform/windows/dpi_utils.cc
 FILE: ../../../flutter/shell/platform/windows/flutter_windows.cc
 FILE: ../../../flutter/shell/platform/windows/key_event_handler.cc
 FILE: ../../../flutter/shell/platform/windows/key_event_handler.h
@@ -1117,8 +1119,6 @@ FILE: ../../../flutter/shell/platform/windows/platform_handler.h
 FILE: ../../../flutter/shell/platform/windows/public/flutter_windows.h
 FILE: ../../../flutter/shell/platform/windows/text_input_plugin.cc
 FILE: ../../../flutter/shell/platform/windows/text_input_plugin.h
-FILE: ../../../flutter/shell/platform/windows/win32_dpi_helper.cc
-FILE: ../../../flutter/shell/platform/windows/win32_dpi_helper.h
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.cc
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.h
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.cc
diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index 36da0da25323f..8c27b050d8853 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -43,6 +43,8 @@ source_set("flutter_windows_source") {
   sources = [
     "angle_surface_manager.cc",
     "angle_surface_manager.h",
+    "dpi_utils.h",
+    "dpi_utils.cc",
     "flutter_windows.cc",
     "key_event_handler.cc",
     "key_event_handler.h",
@@ -51,8 +53,6 @@ source_set("flutter_windows_source") {
     "platform_handler.h",
     "text_input_plugin.cc",
     "text_input_plugin.h",
-    "win32_dpi_helper.cc",
-    "win32_dpi_helper.h",
     "win32_flutter_window.cc",
     "win32_flutter_window.h",
     "win32_task_runner.cc",
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index da9dd9bc96032..023947521d8e7 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -19,7 +19,7 @@
 #include "flutter/shell/platform/windows/keyboard_hook_handler.h"
 #include "flutter/shell/platform/windows/platform_handler.h"
 #include "flutter/shell/platform/windows/text_input_plugin.h"
-#include "flutter/shell/platform/windows/win32_dpi_helper.h"
+#include "flutter/shell/platform/windows/dpi_utils.h"
 #include "flutter/shell/platform/windows/win32_flutter_window.h"
 #include "flutter/shell/platform/windows/win32_task_runner.h"
 #include "flutter/shell/platform/windows/window_state.h"
@@ -150,7 +150,6 @@ FlutterDesktopViewControllerRef FlutterDesktopCreateViewController(
   }
   state->view->SetState(engine_state->engine);
   state->engine_state = std::move(engine_state);
-  state->dpi_helper = std::make_unique<flutter::Win32DpiHelper>();
   return state;
 }
 
@@ -185,10 +184,14 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view) {
 }
 
 UINT FlutterDesktopViewGetDpiForView(HWND hwnd) {
-  static flutter::Win32DpiHelper* dpi_helper = new flutter::Win32DpiHelper();
-  return dpi_helper->GetDpi(hwnd);
+  return flutter::GetDpiForView(hwnd);
 }
 
+ BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd) {
+   return flutter::EnableNonClientDpiScaling(hwnd);
+ }
+
+
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
                                                 const char* icu_data_path,
                                                 const char** arguments,
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index 958d7464acf53..b87a5d6a130f8 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -78,6 +78,7 @@ FlutterDesktopProcessMessages(FlutterDesktopViewControllerRef controller);
 FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
 
 FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForView(HWND hwnd);
+FLUTTER_EXPORT BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd);
 
 // Runs an instance of a headless Flutter engine.
 //
diff --git a/shell/platform/windows/win32_dpi_helper.cc b/shell/platform/windows/win32_dpi_helper.cc
deleted file mode 100644
index 9fef9de0fe7a7..0000000000000
--- a/shell/platform/windows/win32_dpi_helper.cc
+++ /dev/null
@@ -1,94 +0,0 @@
-#include "flutter/shell/platform/windows/win32_dpi_helper.h"
-
-#include <iostream>
-namespace flutter {
-
-namespace {
-
-constexpr UINT kDefaultDpi = 96;
-
-template <typename T>
-bool AssignProcAddress(HMODULE comBaseModule, const char* name, T*& outProc) {
-  outProc = reinterpret_cast<T*>(GetProcAddress(comBaseModule, name));
-  return *outProc != nullptr;
-}
-
-}  // namespace
-
-Win32DpiHelper::Win32DpiHelper() {
-  user32_module_ = LoadLibraryA("User32.dll");
-  if (user32_module_ == nullptr) {
-    return;
-  }
-}
-
-Win32DpiHelper::~Win32DpiHelper() {
-  if (user32_module_ != nullptr) {
-    FreeLibrary(user32_module_);
-  }
-  if (shlib_module_ != nullptr) {
-    FreeLibrary(shlib_module_);
-  }
-}
-
-BOOL Win32DpiHelper::IsDpiPerWindowSupportedForWindow(HWND hwnd) {
-  if (!dpi_for_window_api_loaded_) {
-    dpi_for_window_supported_ =
-        (AssignProcAddress(user32_module_, "GetDpiForWindow",
-                           get_dpi_for_window_) &&
-         AssignProcAddress(user32_module_, "GetWindowDpiAwarenessContext",
-                           get_window_dpi_awareness_context_) &&
-         AssignProcAddress(user32_module_, "AreDpiAwarenessContextsEqual",
-                           are_dpi_awareness_contexts_equal));
-    dpi_for_window_api_loaded_ = true;
-  }
-  if (!dpi_for_window_supported_) {
-    return false;
-  }
-
-  DPI_AWARENESS_CONTEXT context = get_window_dpi_awareness_context_(hwnd);
-  return are_dpi_awareness_contexts_equal(
-      context, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
-}
-
-BOOL Win32DpiHelper::IsDpiPerMonitorSupported() {
-  if (!dpi_for_monitor_api_loaded_) {
-    shlib_module_ = LoadLibraryA("Shcore.dll");
-    if (shlib_module_ == nullptr) {
-      return false;
-    }
-    dpi_for_monitor_supported_ =
-        (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
-                           get_dpi_for_monitor_) &&
-         AssignProcAddress(user32_module_, "MonitorFromWindow",
-                           monitor_from_window_));
-    dpi_for_monitor_api_loaded_ = true;
-  }
-  return dpi_for_monitor_supported_;
-}
-
-UINT Win32DpiHelper::GetDpi(HWND hwnd) {
-  // GetDpiForWindow returns the DPI for any awareness mode. If not available,
-  // fallback to a per monitor, system, or default DPI.
-  if (hwnd != nullptr && IsDpiPerWindowSupportedForWindow(hwnd)) {
-    std::cerr << "v2\n";
-    return get_dpi_for_window_(hwnd);
-  }
-
-  if (IsDpiPerMonitorSupported()) {
-    std::cerr << "monitor\n";
-
-    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
-    UINT dpi_x = 0, dpi_y = 0;
-    HRESULT result =
-        get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
-    return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
-  }
-  std::cerr << "system\n";
-
-  HDC hdc = GetDC(hwnd);
-  UINT dpi = GetDeviceCaps(hdc, LOGPIXELSX);
-  ReleaseDC(hwnd, hdc);
-  return dpi;
-}
-}  // namespace flutter
diff --git a/shell/platform/windows/win32_dpi_helper.h b/shell/platform/windows/win32_dpi_helper.h
deleted file mode 100644
index 63a1d357e4b29..0000000000000
--- a/shell/platform/windows/win32_dpi_helper.h
+++ /dev/null
@@ -1,57 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef FLUTTER_SHELL_PLATFORM_WINDOWS_DPI_HELPER_H_
-#define FLUTTER_SHELL_PLATFORM_WINDOWS_DPI_HELPER_H_
-
-#include <ShellScalingApi.h>
-#include <VersionHelpers.h>
-
-namespace flutter {
-
-/// A helper class for abstracting various Windows DPI related functions across
-/// Windows OS versions.
-class Win32DpiHelper {
- public:
-  Win32DpiHelper();
-
-  ~Win32DpiHelper();
-
-  /// Returns the current DPI. Supports all DPI awareness modes, and is backward
-  /// compatible down to Windows Vista.
-  UINT GetDpi(HWND);
-
- private:
- BOOL IsDpiPerWindowSupportedForWindow(HWND hwnd);
- BOOL IsDpiPerMonitorSupported();
-
-  using GetDpiForWindow_ = UINT __stdcall(HWND);
-  using GetDpiForMonitor_ = HRESULT __stdcall(HMONITOR hmonitor,
-                                              MONITOR_DPI_TYPE dpiType,
-                                              UINT* dpiX,
-                                              UINT* dpiY);
-  using MonitorFromWindow_ = HMONITOR __stdcall(HWND hwnd, DWORD dwFlags);
-  using GetWindowDpiAwarenessContext_ =
-      DPI_AWARENESS_CONTEXT __stdcall(HWND hwnd);
-  using AreDpiAwarenessContextsEqual_ =
-      BOOL __stdcall(DPI_AWARENESS_CONTEXT dpiContextA,
-                     DPI_AWARENESS_CONTEXT dpiContextB);
-
-  GetDpiForWindow_* get_dpi_for_window_ = nullptr;
-  GetDpiForMonitor_* get_dpi_for_monitor_ = nullptr;
-  MonitorFromWindow_* monitor_from_window_ = nullptr;
-  GetWindowDpiAwarenessContext_* get_window_dpi_awareness_context_ = nullptr;
-  AreDpiAwarenessContextsEqual_* are_dpi_awareness_contexts_equal = nullptr;
-
-  HMODULE user32_module_ = nullptr;
-  HMODULE shlib_module_ = nullptr;
-  bool dpi_for_window_supported_ = false;
-  bool dpi_for_monitor_supported_ = false;
-  bool dpi_for_window_api_loaded_ = false;
-  bool dpi_for_monitor_api_loaded_ = false;
-};
-
-}  // namespace flutter
-
-#endif  // FLUTTER_SHELL_PLATFORM_WINDOWS_DPI_HELPER_H_
diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index ccc9095a56c13..20e84f5d76d95 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -4,11 +4,16 @@
 
 #include "flutter/shell/platform/windows/win32_window.h"
 
+#include "dpi_utils.h"
 #include <iostream>
 
 namespace flutter {
 
-Win32Window::Win32Window() {}
+Win32Window::Win32Window() {
+   current_dpi_ = GetDpiForView(nullptr);
+    std::cerr << "Current dpi" << std::endl;
+    std::cerr << current_dpi_ << std::endl;
+}
 
 Win32Window::~Win32Window() {
   Destroy();
@@ -76,9 +81,6 @@ LRESULT CALLBACK Win32Window::WndProc(HWND const window,
                      reinterpret_cast<LONG_PTR>(cs->lpCreateParams));
 
     auto that = static_cast<Win32Window*>(cs->lpCreateParams);
-    that->current_dpi_ = that->dpi_helper_->GetDpi(window);
-    std::cerr << "Current dpi" << std::endl;
-    std::cerr << that->current_dpi_ << std::endl;
 
     that->window_handle_ = window;
   } else if (Win32Window* that = GetThisFromHandle(window)) {
@@ -272,7 +274,7 @@ Win32Window::HandleDpiChange(HWND hwnd,
     // The DPI is only passed for DPI change messages on top level windows,
     // hence call function to get DPI if needed.
     if (uDpi == 0) {
-      uDpi = dpi_helper_->GetDpi(hwnd);
+      uDpi = GetDpiForView(hwnd);
        std::cerr << "New dpi" << std::endl;
     std::cerr << uDpi << std::endl;
     }
diff --git a/shell/platform/windows/win32_window.h b/shell/platform/windows/win32_window.h
index 63a00c355dea6..c24cab78d3da9 100644
--- a/shell/platform/windows/win32_window.h
+++ b/shell/platform/windows/win32_window.h
@@ -11,7 +11,6 @@
 #include <memory>
 #include <string>
 
-#include "flutter/shell/platform/windows/win32_dpi_helper.h"
 
 namespace flutter {
 
@@ -172,11 +171,6 @@ class Win32Window {
   // Member variable to hold the window title.
   std::wstring window_class_name_;
 
-  // Member variable referencing an instance of dpi_helper used to abstract some
-  // aspects of win32 High DPI handling across different OS versions.
-  std::unique_ptr<Win32DpiHelper> dpi_helper_ =
-      std::make_unique<Win32DpiHelper>();
-
   // Set to true to be notified when the mouse leaves the window.
   bool tracking_mouse_leave_ = false;
 
diff --git a/shell/platform/windows/window_state.h b/shell/platform/windows/window_state.h
index 30bb39524f2bd..254ab46c2ead9 100644
--- a/shell/platform/windows/window_state.h
+++ b/shell/platform/windows/window_state.h
@@ -12,7 +12,6 @@
 #include "flutter/shell/platform/windows/keyboard_hook_handler.h"
 #include "flutter/shell/platform/windows/platform_handler.h"
 #include "flutter/shell/platform/windows/text_input_plugin.h"
-#include "flutter/shell/platform/windows/win32_dpi_helper.h"
 #include "flutter/shell/platform/windows/win32_task_runner.h"
 
 struct flutter::Win32FlutterWindow;
@@ -28,8 +27,6 @@ struct FlutterDesktopViewControllerState {
 
   // The window handle given to API clients.
   std::unique_ptr<FlutterDesktopView> view_wrapper;
-
-  std::unique_ptr<flutter::Win32DpiHelper> dpi_helper;
 };
 
 // Opaque reference for the native windows itself. This is separate from the

From 0ac5ce502bb6d3a0bc4320c380866e1d8bf202ee Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 11:28:23 -0800
Subject: [PATCH 04/38] Now with scaling

---
 shell/platform/windows/dpi_utils.cc | 170 ++++++++++++++++++++++++++++
 shell/platform/windows/dpi_utils.h  |  17 +++
 2 files changed, 187 insertions(+)
 create mode 100644 shell/platform/windows/dpi_utils.cc
 create mode 100644 shell/platform/windows/dpi_utils.h

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
new file mode 100644
index 0000000000000..7d2ecd32b5cf3
--- /dev/null
+++ b/shell/platform/windows/dpi_utils.cc
@@ -0,0 +1,170 @@
+#include "dpi_utils.h"
+
+#include <ShellScalingApi.h>
+
+#include <iostream>
+
+namespace flutter {
+
+namespace {
+
+constexpr UINT kDefaultDpi = 96;
+
+template <typename T>
+bool AssignProcAddress(HMODULE comBaseModule, const char* name, T*& outProc) {
+  outProc = reinterpret_cast<T*>(GetProcAddress(comBaseModule, name));
+  return *outProc != nullptr;
+}
+
+}  // namespace
+
+/// A helper class for abstracting various Windows DPI related functions across
+/// Windows OS versions.
+class Win32DpiHelper {
+ public:
+  Win32DpiHelper();
+
+  ~Win32DpiHelper();
+
+  /// Returns the current DPI. Supports all DPI awareness modes, and is backward
+  /// compatible down to Windows Vista.
+  UINT GetDpi(HWND);
+  BOOL EnableNonClientDpiScaling(HWND hwnd);
+
+ private:
+  BOOL IsDpiPerWindowSupportedForWindow(HWND hwnd);
+  BOOL IsDpiPerMonitorSupported();
+
+  using GetDpiForWindow_ = UINT __stdcall(HWND);
+  using GetDpiForMonitor_ = HRESULT __stdcall(HMONITOR hmonitor,
+                                              MONITOR_DPI_TYPE dpiType,
+                                              UINT* dpiX,
+                                              UINT* dpiY);
+  using MonitorFromWindow_ = HMONITOR __stdcall(HWND hwnd, DWORD dwFlags);
+  using EnableNonClientDpiScaling_ = BOOL __stdcall(HWND hwnd);
+  using GetWindowDpiAwarenessContext_ =
+      DPI_AWARENESS_CONTEXT __stdcall(HWND hwnd);
+  using AreDpiAwarenessContextsEqual_ =
+      BOOL __stdcall(DPI_AWARENESS_CONTEXT dpiContextA,
+                     DPI_AWARENESS_CONTEXT dpiContextB);
+
+  GetDpiForWindow_* get_dpi_for_window_ = nullptr;
+  GetDpiForMonitor_* get_dpi_for_monitor_ = nullptr;
+  MonitorFromWindow_* monitor_from_window_ = nullptr;
+  EnableNonClientDpiScaling_* enable_non_client_dpi_scaling_ = nullptr;
+  GetWindowDpiAwarenessContext_* get_window_dpi_awareness_context_ = nullptr;
+  AreDpiAwarenessContextsEqual_* are_dpi_awareness_contexts_equal = nullptr;
+
+  HMODULE user32_module_ = nullptr;
+  HMODULE shlib_module_ = nullptr;
+  bool dpi_for_window_supported_ = false;
+  bool dpi_for_monitor_supported_ = false;
+  bool dpi_for_window_api_loaded_ = false;
+  bool dpi_for_monitor_api_loaded_ = false;
+};
+
+Win32DpiHelper::Win32DpiHelper() {
+  user32_module_ = LoadLibraryA("User32.dll");
+  if (user32_module_ == nullptr) {
+    return;
+  }
+}
+
+Win32DpiHelper::~Win32DpiHelper() {
+  if (user32_module_ != nullptr) {
+    FreeLibrary(user32_module_);
+  }
+  if (shlib_module_ != nullptr) {
+    FreeLibrary(shlib_module_);
+  }
+}
+
+BOOL Win32DpiHelper::IsDpiPerWindowSupportedForWindow(HWND hwnd) {
+  if (!dpi_for_window_api_loaded_) {
+    dpi_for_window_supported_ =
+        (AssignProcAddress(user32_module_, "GetDpiForWindow",
+                           get_dpi_for_window_) &&
+         AssignProcAddress(user32_module_, "GetWindowDpiAwarenessContext",
+                           get_window_dpi_awareness_context_) &&
+         AssignProcAddress(user32_module_, "AreDpiAwarenessContextsEqual",
+                           are_dpi_awareness_contexts_equal));
+    dpi_for_window_api_loaded_ = true;
+  }
+  if (!dpi_for_window_supported_) {
+    return false;
+  }
+  DPI_AWARENESS_CONTEXT context = get_window_dpi_awareness_context_(hwnd);
+  std::cerr << context << std::endl;
+
+  bool is_v2 = are_dpi_awareness_contexts_equal(
+      context, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+  if (!is_v2) {
+    AssignProcAddress(user32_module_, "EnableNonClientDpiScaling",
+                      enable_non_client_dpi_scaling_);
+  }
+  return is_v2;
+}
+
+BOOL Win32DpiHelper::IsDpiPerMonitorSupported() {
+  if (!dpi_for_monitor_api_loaded_) {
+    shlib_module_ = LoadLibraryA("Shcore.dll");
+    if (shlib_module_ == nullptr) {
+      return false;
+    }
+    dpi_for_monitor_supported_ =
+        (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
+                           get_dpi_for_monitor_) &&
+         AssignProcAddress(user32_module_, "MonitorFromWindow",
+                           monitor_from_window_));
+    dpi_for_monitor_api_loaded_ = true;
+  }
+  return dpi_for_monitor_supported_;
+}
+
+BOOL Win32DpiHelper::EnableNonClientDpiScaling(HWND hwnd) {
+  if (enable_non_client_dpi_scaling_ == nullptr) {
+    std::cerr << "Not loaded\n";
+    return false;
+  }
+  return enable_non_client_dpi_scaling_(hwnd);
+}
+
+UINT Win32DpiHelper::GetDpi(HWND hwnd) {
+  // GetDpiForWindow returns the DPI for any awareness mode. If not available,
+  // fallback to a per monitor, system, or default DPI.
+  if (IsDpiPerWindowSupportedForWindow(hwnd) && hwnd != nullptr) {
+    std::cerr << "v2\n";
+    return get_dpi_for_window_(hwnd);
+  }
+
+  if (IsDpiPerMonitorSupported()) {
+    std::cerr << "monitor\n";
+
+    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
+    UINT dpi_x = 0, dpi_y = 0;
+    HRESULT result =
+        get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
+    return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
+  }
+  std::cerr << "system\n";
+
+  HDC hdc = GetDC(hwnd);
+  UINT dpi = GetDeviceCaps(hdc, LOGPIXELSX);
+  ReleaseDC(hwnd, hdc);
+  return dpi;
+}
+
+Win32DpiHelper* GetHelper() {
+  static Win32DpiHelper* dpi_helper = new Win32DpiHelper();
+  return dpi_helper;
+}
+
+UINT GetDpiForView(HWND hwnd) {
+  return GetHelper()->GetDpi(hwnd);
+}
+
+BOOL EnableNonClientDpiScaling(HWND hwnd) {
+  return GetHelper()->EnableNonClientDpiScaling(hwnd);
+}
+
+}  // namespace flutter
diff --git a/shell/platform/windows/dpi_utils.h b/shell/platform/windows/dpi_utils.h
new file mode 100644
index 0000000000000..47e69c1710c9a
--- /dev/null
+++ b/shell/platform/windows/dpi_utils.h
@@ -0,0 +1,17 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "Windows.h"
+
+#ifndef FLUTTER_SHELL_PLATFORM_WINDOWS_DPI_UTILS_H_
+#define FLUTTER_SHELL_PLATFORM_WINDOWS_DPI_UTILS_H_
+
+namespace flutter {
+
+UINT GetDpiForView(HWND hwnd);
+BOOL EnableNonClientDpiScaling(HWND hwnd);
+
+}  // namespace flutter
+
+#endif  // FLUTTER_SHELL_PLATFORM_WINDOWS_DPI_UTILS_H_

From 3bc93ab0ec665d03741eb0809a4886c8c29854cc Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 13:54:04 -0800
Subject: [PATCH 05/38] Format

---
 shell/platform/windows/dpi_utils.cc             | 17 +++++------------
 shell/platform/windows/flutter_windows.cc       |  9 ++++-----
 shell/platform/windows/public/flutter_windows.h |  9 +++++++--
 3 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 7d2ecd32b5cf3..646b6125c1265 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -2,8 +2,6 @@
 
 #include <ShellScalingApi.h>
 
-#include <iostream>
-
 namespace flutter {
 
 namespace {
@@ -29,6 +27,9 @@ class Win32DpiHelper {
   /// Returns the current DPI. Supports all DPI awareness modes, and is backward
   /// compatible down to Windows Vista.
   UINT GetDpi(HWND);
+
+  /// Enables scaling of non-client UI (scrolling bars, title bars, etc). Only
+  /// supported or Per-Monitor V1 DPI awareness mode.
   BOOL EnableNonClientDpiScaling(HWND hwnd);
 
  private:
@@ -94,8 +95,6 @@ BOOL Win32DpiHelper::IsDpiPerWindowSupportedForWindow(HWND hwnd) {
     return false;
   }
   DPI_AWARENESS_CONTEXT context = get_window_dpi_awareness_context_(hwnd);
-  std::cerr << context << std::endl;
-
   bool is_v2 = are_dpi_awareness_contexts_equal(
       context, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
   if (!is_v2) {
@@ -123,7 +122,6 @@ BOOL Win32DpiHelper::IsDpiPerMonitorSupported() {
 
 BOOL Win32DpiHelper::EnableNonClientDpiScaling(HWND hwnd) {
   if (enable_non_client_dpi_scaling_ == nullptr) {
-    std::cerr << "Not loaded\n";
     return false;
   }
   return enable_non_client_dpi_scaling_(hwnd);
@@ -131,23 +129,19 @@ BOOL Win32DpiHelper::EnableNonClientDpiScaling(HWND hwnd) {
 
 UINT Win32DpiHelper::GetDpi(HWND hwnd) {
   // GetDpiForWindow returns the DPI for any awareness mode. If not available,
-  // fallback to a per monitor, system, or default DPI.
+  // or no |hwnd| is provided. fallback to a per monitor, system, or default
+  // DPI.
   if (IsDpiPerWindowSupportedForWindow(hwnd) && hwnd != nullptr) {
-    std::cerr << "v2\n";
     return get_dpi_for_window_(hwnd);
   }
 
   if (IsDpiPerMonitorSupported()) {
-    std::cerr << "monitor\n";
-
     HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
         get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
     return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
   }
-  std::cerr << "system\n";
-
   HDC hdc = GetDC(hwnd);
   UINT dpi = GetDeviceCaps(hdc, LOGPIXELSX);
   ReleaseDC(hwnd, hdc);
@@ -166,5 +160,4 @@ UINT GetDpiForView(HWND hwnd) {
 BOOL EnableNonClientDpiScaling(HWND hwnd) {
   return GetHelper()->EnableNonClientDpiScaling(hwnd);
 }
-
 }  // namespace flutter
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index 023947521d8e7..4f2a284b3b746 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -15,11 +15,11 @@
 #include "flutter/shell/platform/common/cpp/client_wrapper/include/flutter/plugin_registrar.h"
 #include "flutter/shell/platform/common/cpp/incoming_message_dispatcher.h"
 #include "flutter/shell/platform/embedder/embedder.h"
+#include "flutter/shell/platform/windows/dpi_utils.h"
 #include "flutter/shell/platform/windows/key_event_handler.h"
 #include "flutter/shell/platform/windows/keyboard_hook_handler.h"
 #include "flutter/shell/platform/windows/platform_handler.h"
 #include "flutter/shell/platform/windows/text_input_plugin.h"
-#include "flutter/shell/platform/windows/dpi_utils.h"
 #include "flutter/shell/platform/windows/win32_flutter_window.h"
 #include "flutter/shell/platform/windows/win32_task_runner.h"
 #include "flutter/shell/platform/windows/window_state.h"
@@ -187,10 +187,9 @@ UINT FlutterDesktopViewGetDpiForView(HWND hwnd) {
   return flutter::GetDpiForView(hwnd);
 }
 
- BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd) {
-   return flutter::EnableNonClientDpiScaling(hwnd);
- }
-
+BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd) {
+  return flutter::EnableNonClientDpiScaling(hwnd);
+}
 
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
                                                 const char* icu_data_path,
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index b87a5d6a130f8..f20b92ded6ecb 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -8,12 +8,11 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "Windows.h"
 #include "flutter_export.h"
 #include "flutter_messenger.h"
 #include "flutter_plugin_registrar.h"
 
-#include "Windows.h"
-
 #if defined(__cplusplus)
 extern "C" {
 #endif
@@ -77,7 +76,13 @@ FlutterDesktopProcessMessages(FlutterDesktopViewControllerRef controller);
 // Return backing HWND for manipulation in host application.
 FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
 
+// Gets the DPI for a given |hwnd|, depending on the supported APIs per
+// windows version and DPI awareness mode. If nullptr is passed, returns the DPI
+// of the nearest monitor.
 FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForView(HWND hwnd);
+
+// Use only for apps that support Per-Monitor V1 awereness mode. Not necessary
+// for Per-Monitor V2.
 FLUTTER_EXPORT BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd);
 
 // Runs an instance of a headless Flutter engine.

From 1990c7b335cdb191c6762e54d0f578d4e39f59a4 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 16:22:09 -0800
Subject: [PATCH 06/38] Clean

---
 shell/platform/windows/dpi_utils.cc           | 74 +++++--------------
 shell/platform/windows/dpi_utils.h            |  2 +-
 shell/platform/windows/flutter_windows.cc     |  4 +-
 .../platform/windows/public/flutter_windows.h |  2 +-
 shell/platform/windows/win32_window.cc        | 14 ++--
 5 files changed, 28 insertions(+), 68 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 646b6125c1265..721c7eed32147 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -29,13 +29,10 @@ class Win32DpiHelper {
   UINT GetDpi(HWND);
 
   /// Enables scaling of non-client UI (scrolling bars, title bars, etc). Only
-  /// supported or Per-Monitor V1 DPI awareness mode.
+  /// supported on Per-Monitor V1 DPI awareness mode.
   BOOL EnableNonClientDpiScaling(HWND hwnd);
 
  private:
-  BOOL IsDpiPerWindowSupportedForWindow(HWND hwnd);
-  BOOL IsDpiPerMonitorSupported();
-
   using GetDpiForWindow_ = UINT __stdcall(HWND);
   using GetDpiForMonitor_ = HRESULT __stdcall(HMONITOR hmonitor,
                                               MONITOR_DPI_TYPE dpiType,
@@ -43,32 +40,35 @@ class Win32DpiHelper {
                                               UINT* dpiY);
   using MonitorFromWindow_ = HMONITOR __stdcall(HWND hwnd, DWORD dwFlags);
   using EnableNonClientDpiScaling_ = BOOL __stdcall(HWND hwnd);
-  using GetWindowDpiAwarenessContext_ =
-      DPI_AWARENESS_CONTEXT __stdcall(HWND hwnd);
-  using AreDpiAwarenessContextsEqual_ =
-      BOOL __stdcall(DPI_AWARENESS_CONTEXT dpiContextA,
-                     DPI_AWARENESS_CONTEXT dpiContextB);
 
   GetDpiForWindow_* get_dpi_for_window_ = nullptr;
   GetDpiForMonitor_* get_dpi_for_monitor_ = nullptr;
   MonitorFromWindow_* monitor_from_window_ = nullptr;
   EnableNonClientDpiScaling_* enable_non_client_dpi_scaling_ = nullptr;
-  GetWindowDpiAwarenessContext_* get_window_dpi_awareness_context_ = nullptr;
-  AreDpiAwarenessContextsEqual_* are_dpi_awareness_contexts_equal = nullptr;
 
   HMODULE user32_module_ = nullptr;
   HMODULE shlib_module_ = nullptr;
   bool dpi_for_window_supported_ = false;
   bool dpi_for_monitor_supported_ = false;
-  bool dpi_for_window_api_loaded_ = false;
-  bool dpi_for_monitor_api_loaded_ = false;
 };
 
 Win32DpiHelper::Win32DpiHelper() {
   user32_module_ = LoadLibraryA("User32.dll");
-  if (user32_module_ == nullptr) {
+  shlib_module_ = LoadLibraryA("Shcore.dll");
+  if (shlib_module_ == nullptr && user32_module_ == nullptr) {
     return;
   }
+
+  dpi_for_window_supported_ =
+      (AssignProcAddress(user32_module_, "GetDpiForWindow",
+                         get_dpi_for_window_) &&
+       AssignProcAddress(user32_module_, "EnableNonClientDpiScaling",
+                         enable_non_client_dpi_scaling_));
+  dpi_for_monitor_supported_ =
+      (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
+                         get_dpi_for_monitor_) &&
+       AssignProcAddress(user32_module_, "MonitorFromWindow",
+                         monitor_from_window_));
 }
 
 Win32DpiHelper::~Win32DpiHelper() {
@@ -80,46 +80,6 @@ Win32DpiHelper::~Win32DpiHelper() {
   }
 }
 
-BOOL Win32DpiHelper::IsDpiPerWindowSupportedForWindow(HWND hwnd) {
-  if (!dpi_for_window_api_loaded_) {
-    dpi_for_window_supported_ =
-        (AssignProcAddress(user32_module_, "GetDpiForWindow",
-                           get_dpi_for_window_) &&
-         AssignProcAddress(user32_module_, "GetWindowDpiAwarenessContext",
-                           get_window_dpi_awareness_context_) &&
-         AssignProcAddress(user32_module_, "AreDpiAwarenessContextsEqual",
-                           are_dpi_awareness_contexts_equal));
-    dpi_for_window_api_loaded_ = true;
-  }
-  if (!dpi_for_window_supported_) {
-    return false;
-  }
-  DPI_AWARENESS_CONTEXT context = get_window_dpi_awareness_context_(hwnd);
-  bool is_v2 = are_dpi_awareness_contexts_equal(
-      context, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
-  if (!is_v2) {
-    AssignProcAddress(user32_module_, "EnableNonClientDpiScaling",
-                      enable_non_client_dpi_scaling_);
-  }
-  return is_v2;
-}
-
-BOOL Win32DpiHelper::IsDpiPerMonitorSupported() {
-  if (!dpi_for_monitor_api_loaded_) {
-    shlib_module_ = LoadLibraryA("Shcore.dll");
-    if (shlib_module_ == nullptr) {
-      return false;
-    }
-    dpi_for_monitor_supported_ =
-        (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
-                           get_dpi_for_monitor_) &&
-         AssignProcAddress(user32_module_, "MonitorFromWindow",
-                           monitor_from_window_));
-    dpi_for_monitor_api_loaded_ = true;
-  }
-  return dpi_for_monitor_supported_;
-}
-
 BOOL Win32DpiHelper::EnableNonClientDpiScaling(HWND hwnd) {
   if (enable_non_client_dpi_scaling_ == nullptr) {
     return false;
@@ -131,11 +91,11 @@ UINT Win32DpiHelper::GetDpi(HWND hwnd) {
   // GetDpiForWindow returns the DPI for any awareness mode. If not available,
   // or no |hwnd| is provided. fallback to a per monitor, system, or default
   // DPI.
-  if (IsDpiPerWindowSupportedForWindow(hwnd) && hwnd != nullptr) {
+  if (dpi_for_window_supported_ && hwnd != nullptr) {
     return get_dpi_for_window_(hwnd);
   }
 
-  if (IsDpiPerMonitorSupported()) {
+  if (dpi_for_monitor_supported_) {
     HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
@@ -153,7 +113,7 @@ Win32DpiHelper* GetHelper() {
   return dpi_helper;
 }
 
-UINT GetDpiForView(HWND hwnd) {
+UINT GetDpiForHWND(HWND hwnd) {
   return GetHelper()->GetDpi(hwnd);
 }
 
diff --git a/shell/platform/windows/dpi_utils.h b/shell/platform/windows/dpi_utils.h
index 47e69c1710c9a..5baa21c454e27 100644
--- a/shell/platform/windows/dpi_utils.h
+++ b/shell/platform/windows/dpi_utils.h
@@ -9,7 +9,7 @@
 
 namespace flutter {
 
-UINT GetDpiForView(HWND hwnd);
+UINT GetDpiForHWND(HWND hwnd);
 BOOL EnableNonClientDpiScaling(HWND hwnd);
 
 }  // namespace flutter
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index 4f2a284b3b746..9a9c4118a206c 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -183,8 +183,8 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view) {
   return view->window->GetWindowHandle();
 }
 
-UINT FlutterDesktopViewGetDpiForView(HWND hwnd) {
-  return flutter::GetDpiForView(hwnd);
+UINT FlutterDesktopViewGetDpiForHWND(HWND hwnd) {
+  return flutter::GetDpiForHWND(hwnd);
 }
 
 BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd) {
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index f20b92ded6ecb..06322dfa1e042 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -79,7 +79,7 @@ FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
 // Gets the DPI for a given |hwnd|, depending on the supported APIs per
 // windows version and DPI awareness mode. If nullptr is passed, returns the DPI
 // of the nearest monitor.
-FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForView(HWND hwnd);
+FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForHWND(HWND hwnd);
 
 // Use only for apps that support Per-Monitor V1 awereness mode. Not necessary
 // for Per-Monitor V2.
diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index 20e84f5d76d95..cb0bec81eee5f 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -4,15 +4,17 @@
 
 #include "flutter/shell/platform/windows/win32_window.h"
 
-#include "dpi_utils.h"
 #include <iostream>
 
+#include "dpi_utils.h"
+
 namespace flutter {
 
 Win32Window::Win32Window() {
-   current_dpi_ = GetDpiForView(nullptr);
-    std::cerr << "Current dpi" << std::endl;
-    std::cerr << current_dpi_ << std::endl;
+  // Calling GetDpiForView with no HNWD returns the DPI from the nearest
+  // monitor, which is the best option as an initial DPI. If Per-Monitor V2 is
+  // supported, |current_dpi_| should be updated in the WM_DPICHANGED message.
+  current_dpi_ = GetDpiForHWND(nullptr);
 }
 
 Win32Window::~Win32Window() {
@@ -274,9 +276,7 @@ Win32Window::HandleDpiChange(HWND hwnd,
     // The DPI is only passed for DPI change messages on top level windows,
     // hence call function to get DPI if needed.
     if (uDpi == 0) {
-      uDpi = GetDpiForView(hwnd);
-       std::cerr << "New dpi" << std::endl;
-    std::cerr << uDpi << std::endl;
+      uDpi = GetDpiForHWND(hwnd);
     }
     current_dpi_ = uDpi;
     window->OnDpiScale(uDpi);

From 5d53cb2e1b62cc14786b5449bb7cf8e78c0e1ef9 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 16:36:18 -0800
Subject: [PATCH 07/38] Commetns

---
 shell/platform/windows/dpi_utils.cc | 3 ++-
 shell/platform/windows/dpi_utils.h  | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 721c7eed32147..7915c99b41edd 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -25,7 +25,8 @@ class Win32DpiHelper {
   ~Win32DpiHelper();
 
   /// Returns the current DPI. Supports all DPI awareness modes, and is backward
-  /// compatible down to Windows Vista.
+  /// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI
+  /// for the nearest monitor is available. Otherwise, returns the system's DPI.
   UINT GetDpi(HWND);
 
   /// Enables scaling of non-client UI (scrolling bars, title bars, etc). Only
diff --git a/shell/platform/windows/dpi_utils.h b/shell/platform/windows/dpi_utils.h
index 5baa21c454e27..f460a5224a6c7 100644
--- a/shell/platform/windows/dpi_utils.h
+++ b/shell/platform/windows/dpi_utils.h
@@ -9,7 +9,13 @@
 
 namespace flutter {
 
+/// Returns the current DPI. Supports all DPI awareness modes, and is backward
+/// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI for
+/// the nearest monitor is available. Otherwise, returns the system's DPI.
 UINT GetDpiForHWND(HWND hwnd);
+
+/// Enables scaling of non-client UI (scrolling bars, title bars, etc). Only
+/// supported on Per-Monitor V1 DPI awareness mode.
 BOOL EnableNonClientDpiScaling(HWND hwnd);
 
 }  // namespace flutter

From 869725aa1ae17237c52fb56ce1d8c57957c5b2f2 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 16:40:34 -0800
Subject: [PATCH 08/38] Clean

---
 .../platform/windows/client_wrapper/flutter_view_controller.cc | 1 +
 shell/platform/windows/public/flutter_windows.h                | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/shell/platform/windows/client_wrapper/flutter_view_controller.cc b/shell/platform/windows/client_wrapper/flutter_view_controller.cc
index 296b13e805c47..92a853862d77c 100644
--- a/shell/platform/windows/client_wrapper/flutter_view_controller.cc
+++ b/shell/platform/windows/client_wrapper/flutter_view_controller.cc
@@ -56,4 +56,5 @@ FlutterDesktopPluginRegistrarRef FlutterViewController::GetRegistrarForPlugin(
   }
   return FlutterDesktopGetPluginRegistrar(controller_, plugin_name.c_str());
 }
+
 }  // namespace flutter
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index 06322dfa1e042..ca675c17155b7 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -8,11 +8,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "Windows.h"
 #include "flutter_export.h"
 #include "flutter_messenger.h"
 #include "flutter_plugin_registrar.h"
 
+#include "Windows.h"
+
 #if defined(__cplusplus)
 extern "C" {
 #endif

From e6aa6047f168bb935681d93bff29aa25632b3017 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 31 Jan 2020 17:09:11 -0800
Subject: [PATCH 09/38] Comment

---
 shell/platform/windows/win32_window.cc | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index cb0bec81eee5f..773421981e4ad 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -4,14 +4,12 @@
 
 #include "flutter/shell/platform/windows/win32_window.h"
 
-#include <iostream>
-
 #include "dpi_utils.h"
 
 namespace flutter {
 
 Win32Window::Win32Window() {
-  // Calling GetDpiForView with no HNWD returns the DPI from the nearest
+  // Calling GetDpiForHWND with no HNWD returns the DPI from the nearest
   // monitor, which is the best option as an initial DPI. If Per-Monitor V2 is
   // supported, |current_dpi_| should be updated in the WM_DPICHANGED message.
   current_dpi_ = GetDpiForHWND(nullptr);

From ed6d9a2fef38ee3e163ff611c2e7a95d62c25038 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 3 Feb 2020 14:45:55 -0800
Subject: [PATCH 10/38] Address comments

---
 shell/platform/windows/dpi_utils.cc           | 55 +++++++++----------
 shell/platform/windows/dpi_utils.h            |  6 +-
 shell/platform/windows/flutter_windows.cc     |  4 +-
 .../platform/windows/public/flutter_windows.h |  8 +--
 4 files changed, 36 insertions(+), 37 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 7915c99b41edd..e90ea4a021b74 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -9,13 +9,14 @@ namespace {
 constexpr UINT kDefaultDpi = 96;
 
 template <typename T>
+
+/// Retrieves a function named |name| from a given module in |comBaseModule|
+/// into |outProc|. Returns a bool indicating whether the function was found.
 bool AssignProcAddress(HMODULE comBaseModule, const char* name, T*& outProc) {
   outProc = reinterpret_cast<T*>(GetProcAddress(comBaseModule, name));
   return *outProc != nullptr;
 }
 
-}  // namespace
-
 /// A helper class for abstracting various Windows DPI related functions across
 /// Windows OS versions.
 class Win32DpiHelper {
@@ -27,11 +28,11 @@ class Win32DpiHelper {
   /// Returns the current DPI. Supports all DPI awareness modes, and is backward
   /// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI
   /// for the nearest monitor is available. Otherwise, returns the system's DPI.
-  UINT GetDpi(HWND);
+  UINT GetDpiForWindow(HWND);
 
-  /// Enables scaling of non-client UI (scrolling bars, title bars, etc). Only
-  /// supported on Per-Monitor V1 DPI awareness mode.
-  BOOL EnableNonClientDpiScaling(HWND hwnd);
+  /// Returns the DPI of a given monitor. Defaults to 96 if the API is not
+  /// available.
+  UINT GetDpiForMonitor(HMONITOR);
 
  private:
   using GetDpiForWindow_ = UINT __stdcall(HWND);
@@ -60,11 +61,8 @@ Win32DpiHelper::Win32DpiHelper() {
     return;
   }
 
-  dpi_for_window_supported_ =
-      (AssignProcAddress(user32_module_, "GetDpiForWindow",
-                         get_dpi_for_window_) &&
-       AssignProcAddress(user32_module_, "EnableNonClientDpiScaling",
-                         enable_non_client_dpi_scaling_));
+  dpi_for_window_supported_ = (AssignProcAddress(
+      user32_module_, "GetDpiForWindow", get_dpi_for_window_));
   dpi_for_monitor_supported_ =
       (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
                          get_dpi_for_monitor_) &&
@@ -81,27 +79,17 @@ Win32DpiHelper::~Win32DpiHelper() {
   }
 }
 
-BOOL Win32DpiHelper::EnableNonClientDpiScaling(HWND hwnd) {
-  if (enable_non_client_dpi_scaling_ == nullptr) {
-    return false;
-  }
-  return enable_non_client_dpi_scaling_(hwnd);
-}
-
-UINT Win32DpiHelper::GetDpi(HWND hwnd) {
+UINT Win32DpiHelper::GetDpiForWindow(HWND hwnd) {
   // GetDpiForWindow returns the DPI for any awareness mode. If not available,
-  // or no |hwnd| is provided. fallback to a per monitor, system, or default
+  // or no |hwnd| is provided, fallback to a per monitor, system, or default
   // DPI.
   if (dpi_for_window_supported_ && hwnd != nullptr) {
     return get_dpi_for_window_(hwnd);
   }
 
   if (dpi_for_monitor_supported_) {
-    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTONEAREST);
-    UINT dpi_x = 0, dpi_y = 0;
-    HRESULT result =
-        get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
-    return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
+    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTOPRIMARY);
+    return GetDpiForMonitor(monitor);
   }
   HDC hdc = GetDC(hwnd);
   UINT dpi = GetDeviceCaps(hdc, LOGPIXELSX);
@@ -109,16 +97,27 @@ UINT Win32DpiHelper::GetDpi(HWND hwnd) {
   return dpi;
 }
 
+UINT Win32DpiHelper::GetDpiForMonitor(HMONITOR monitor) {
+  if (dpi_for_monitor_supported_) {
+    UINT dpi_x = 0, dpi_y = 0;
+    HRESULT result =
+        get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
+    return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
+  }
+  return kDefaultDpi;
+}
+
 Win32DpiHelper* GetHelper() {
   static Win32DpiHelper* dpi_helper = new Win32DpiHelper();
   return dpi_helper;
 }
+}  // namespace
 
 UINT GetDpiForHWND(HWND hwnd) {
-  return GetHelper()->GetDpi(hwnd);
+  return GetHelper()->GetDpiForWindow(hwnd);
 }
 
-BOOL EnableNonClientDpiScaling(HWND hwnd) {
-  return GetHelper()->EnableNonClientDpiScaling(hwnd);
+UINT GetDpiForMonitor(HMONITOR monitor) {
+  return GetHelper()->GetDpiForMonitor(monitor);
 }
 }  // namespace flutter
diff --git a/shell/platform/windows/dpi_utils.h b/shell/platform/windows/dpi_utils.h
index f460a5224a6c7..ea3e397951dcc 100644
--- a/shell/platform/windows/dpi_utils.h
+++ b/shell/platform/windows/dpi_utils.h
@@ -14,9 +14,9 @@ namespace flutter {
 /// the nearest monitor is available. Otherwise, returns the system's DPI.
 UINT GetDpiForHWND(HWND hwnd);
 
-/// Enables scaling of non-client UI (scrolling bars, title bars, etc). Only
-/// supported on Per-Monitor V1 DPI awareness mode.
-BOOL EnableNonClientDpiScaling(HWND hwnd);
+/// Returns the DPI of a given monitor. Defaults to 96 if the API is not
+/// available.
+UINT GetDpiForMonitor(HMONITOR monitor);
 
 }  // namespace flutter
 
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index 9a9c4118a206c..e090714f9a4b0 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -187,8 +187,8 @@ UINT FlutterDesktopViewGetDpiForHWND(HWND hwnd) {
   return flutter::GetDpiForHWND(hwnd);
 }
 
-BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd) {
-  return flutter::EnableNonClientDpiScaling(hwnd);
+FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForMonitor(HMONITOR monitor) {
+  return flutter::GetDpiForMonitor(monitor);
 }
 
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index ca675c17155b7..a0598fa1d7320 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -79,12 +79,12 @@ FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
 
 // Gets the DPI for a given |hwnd|, depending on the supported APIs per
 // windows version and DPI awareness mode. If nullptr is passed, returns the DPI
-// of the nearest monitor.
+// of the primary monitor.
 FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForHWND(HWND hwnd);
 
-// Use only for apps that support Per-Monitor V1 awereness mode. Not necessary
-// for Per-Monitor V2.
-FLUTTER_EXPORT BOOL FlutterDesktopEnableNonClientDpiScaling(HWND hwnd);
+// Gets the DPI for a given |monitor|. If the API is not available, a default
+// DPI of 96 is returned.
+FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForMonitor(HMONITOR monitor);
 
 // Runs an instance of a headless Flutter engine.
 //

From 186f56cbf6fdae6e8c0ecaf6ce72ec461ac12336 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 3 Feb 2020 14:50:37 -0800
Subject: [PATCH 11/38] Comment

---
 shell/platform/windows/dpi_utils.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index e90ea4a021b74..053ff4236cc8b 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -10,8 +10,8 @@ constexpr UINT kDefaultDpi = 96;
 
 template <typename T>
 
-/// Retrieves a function named |name| from a given module in |comBaseModule|
-/// into |outProc|. Returns a bool indicating whether the function was found.
+/// Retrieves a function |name| from a given |comBaseModule| into |outProc|.
+/// Returns a bool indicating whether the function was found.
 bool AssignProcAddress(HMODULE comBaseModule, const char* name, T*& outProc) {
   outProc = reinterpret_cast<T*>(GetProcAddress(comBaseModule, name));
   return *outProc != nullptr;

From 7954dbd5c2e170de22a6d4f8809c6d993da4ec54 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Tue, 4 Feb 2020 13:10:36 -0800
Subject: [PATCH 12/38] Review comments

---
 shell/platform/windows/dpi_utils.h              | 2 +-
 shell/platform/windows/flutter_windows.cc       | 4 ++--
 shell/platform/windows/public/flutter_windows.h | 4 ++--
 shell/platform/windows/win32_window.h           | 1 -
 4 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.h b/shell/platform/windows/dpi_utils.h
index ea3e397951dcc..3895a2f2454be 100644
--- a/shell/platform/windows/dpi_utils.h
+++ b/shell/platform/windows/dpi_utils.h
@@ -11,7 +11,7 @@ namespace flutter {
 
 /// Returns the current DPI. Supports all DPI awareness modes, and is backward
 /// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI for
-/// the nearest monitor is available. Otherwise, returns the system's DPI.
+/// the primary monitor. Otherwise, returns the system's DPI.
 UINT GetDpiForHWND(HWND hwnd);
 
 /// Returns the DPI of a given monitor. Defaults to 96 if the API is not
diff --git a/shell/platform/windows/flutter_windows.cc b/shell/platform/windows/flutter_windows.cc
index e090714f9a4b0..58434a35fd253 100644
--- a/shell/platform/windows/flutter_windows.cc
+++ b/shell/platform/windows/flutter_windows.cc
@@ -183,11 +183,11 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view) {
   return view->window->GetWindowHandle();
 }
 
-UINT FlutterDesktopViewGetDpiForHWND(HWND hwnd) {
+UINT FlutterDesktopGetDpiForHWND(HWND hwnd) {
   return flutter::GetDpiForHWND(hwnd);
 }
 
-FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForMonitor(HMONITOR monitor) {
+UINT FlutterDesktopGetDpiForMonitor(HMONITOR monitor) {
   return flutter::GetDpiForMonitor(monitor);
 }
 
diff --git a/shell/platform/windows/public/flutter_windows.h b/shell/platform/windows/public/flutter_windows.h
index a0598fa1d7320..7626be1239c35 100644
--- a/shell/platform/windows/public/flutter_windows.h
+++ b/shell/platform/windows/public/flutter_windows.h
@@ -80,11 +80,11 @@ FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
 // Gets the DPI for a given |hwnd|, depending on the supported APIs per
 // windows version and DPI awareness mode. If nullptr is passed, returns the DPI
 // of the primary monitor.
-FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForHWND(HWND hwnd);
+FLUTTER_EXPORT UINT FlutterDesktopGetDpiForHWND(HWND hwnd);
 
 // Gets the DPI for a given |monitor|. If the API is not available, a default
 // DPI of 96 is returned.
-FLUTTER_EXPORT UINT FlutterDesktopViewGetDpiForMonitor(HMONITOR monitor);
+FLUTTER_EXPORT UINT FlutterDesktopGetDpiForMonitor(HMONITOR monitor);
 
 // Runs an instance of a headless Flutter engine.
 //
diff --git a/shell/platform/windows/win32_window.h b/shell/platform/windows/win32_window.h
index c24cab78d3da9..b0a1e10b3fa3a 100644
--- a/shell/platform/windows/win32_window.h
+++ b/shell/platform/windows/win32_window.h
@@ -11,7 +11,6 @@
 #include <memory>
 #include <string>
 
-
 namespace flutter {
 
 // Struct holding the mouse state. The engine doesn't keep track of which mouse

From c88380752dfe5d76cbcbdc5953ac9402b54b0f07 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Tue, 4 Feb 2020 13:34:44 -0800
Subject: [PATCH 13/38] GN

---
 shell/platform/windows/BUILD.gn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index 8c27b050d8853..df7839784e6fd 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -43,8 +43,8 @@ source_set("flutter_windows_source") {
   sources = [
     "angle_surface_manager.cc",
     "angle_surface_manager.h",
-    "dpi_utils.h",
     "dpi_utils.cc",
+    "dpi_utils.h",
     "flutter_windows.cc",
     "key_event_handler.cc",
     "key_event_handler.h",

From 676237643f541b6a209229ba3c53be364b6005a4 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 14:13:45 -0800
Subject: [PATCH 14/38] Add test

---
 ci/licenses_golden/licenses_flutter           |  2 +-
 shell/platform/windows/BUILD.gn               |  5 +-
 .../testing/stub_flutter_windows_api.cc       |  7 +++
 .../testing/stub_flutter_windows_api.h        |  3 +
 .../testing/win32_flutter_window_test.cc      |  1 +
 .../windows/testing/win32_window_test.cc      | 41 +++++++++++++
 .../windows/testing/win32_window_test.h       | 58 +++++++++++++++++++
 ...s.cc => win32_flutter_window_unittests.cc} |  0
 .../platform/windows/win32_window_unittest.cc | 14 +++++
 testing/run_tests.py                          |  1 +
 10 files changed, 130 insertions(+), 2 deletions(-)
 create mode 100644 shell/platform/windows/testing/win32_window_test.cc
 create mode 100644 shell/platform/windows/testing/win32_window_test.h
 rename shell/platform/windows/{win32_window_unittests.cc => win32_flutter_window_unittests.cc} (100%)
 create mode 100644 shell/platform/windows/win32_window_unittest.cc

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 0fb09282b57c3..964ae44d29eab 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1125,7 +1125,7 @@ FILE: ../../../flutter/shell/platform/windows/win32_task_runner.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.h
 FILE: ../../../flutter/shell/platform/windows/win32_window.cc
 FILE: ../../../flutter/shell/platform/windows/win32_window.h
-FILE: ../../../flutter/shell/platform/windows/win32_window_unittests.cc
+FILE: ../../../flutter/shell/platform/windows/win32_flutter_window_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/window_state.h
 FILE: ../../../flutter/shell/version/version.cc
 FILE: ../../../flutter/shell/version/version.h
diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index df7839784e6fd..4be5ca2d0415c 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -113,7 +113,10 @@ executable("flutter_windows_unittests") {
   sources = [
     "testing/win32_flutter_window_test.cc",
     "testing/win32_flutter_window_test.h",
-    "win32_window_unittests.cc",
+    "testing/win32_window_unittest.cc",
+    "testing/win32_window_unittest.h",
+    "win32_window_unittest.cc",
+    "win32_flutter_window_unittests.cc",
   ]
 
   public_configs = [ "$flutter_root:config" ]
diff --git a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc
index 07dfb8bd7bbbf..b8c00111eda6e 100644
--- a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc
+++ b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc
@@ -78,6 +78,13 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef controller) {
   return reinterpret_cast<HWND>(-1);
 }
 
+UINT FlutterDesktopGetDpiForHWND(HWND hwnd) {
+  if (s_stub_implementation) {
+    return s_stub_implementation->GetDpiForHWND();
+  }
+  return 0;
+}
+
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
                                                 const char* icu_data_path,
                                                 const char** arguments,
diff --git a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h
index 0fd74c5b275f5..c54bcd400c6bc 100644
--- a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h
+++ b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h
@@ -49,6 +49,9 @@ class StubFlutterWindowsApi {
   // Called for FlutterDesktopViewGetHWND.
   virtual HWND ViewGetHWND() { return reinterpret_cast<HWND>(1); }
 
+  // Called for FlutterDesktopGetDpiForHWND.
+  virtual UINT GetDpiForHWND() { return 1; }
+
   // Called for FlutterDesktopRunEngine.
   virtual FlutterDesktopEngineRef RunEngine(const char* assets_path,
                                             const char* icu_data_path,
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.cc b/shell/platform/windows/testing/win32_flutter_window_test.cc
index 080262ae4bf88..cdb06ede12365 100644
--- a/shell/platform/windows/testing/win32_flutter_window_test.cc
+++ b/shell/platform/windows/testing/win32_flutter_window_test.cc
@@ -1,4 +1,5 @@
 #include "flutter/shell/platform/windows/testing/win32_flutter_window_test.h"
+
 #include <iostream>
 
 namespace flutter {
diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
new file mode 100644
index 0000000000000..bf651047290dd
--- /dev/null
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -0,0 +1,41 @@
+#include "flutter/shell/platform/windows/testing/win32_window_unittest.h"
+
+#include <iostream>
+
+namespace flutter {
+namespace testing {
+
+Win32WindowTest::Win32WindowTest() : Win32Window(){};
+
+Win32WindowTest::~Win32WindowTest() = default;
+
+void Win32WindowTest::OnDpiScale(unsigned int dpi){};
+
+// When DesktopWindow notifies that a WM_Size message has come in
+// lets FlutterEngine know about the new size.
+void Win32WindowTest::OnResize(unsigned int width, unsigned int height) {}
+
+void Win32WindowTest::OnPointerMove(double x, double y) {}
+
+void Win32WindowTest::OnPointerDown(double x, double y, UINT button) {}
+
+void Win32WindowTest::OnPointerUp(double x, double y, UINT button) {}
+
+void Win32WindowTest::OnPointerLeave() {}
+
+void Win32WindowTest::OnChar(char32_t code_point) {}
+
+void Win32WindowTest::OnKey(int key, int scancode, int action, int mods) {}
+
+void Win32WindowTest::OnScroll(double delta_x, double delta_y) {}
+
+void Win32WindowTest::OnClose() {}
+
+void Win32WindowTest::OnFontChange() {}
+
+UINT Win32WindowTest::GetDpi() {
+  return GetCurrentDPI();
+}
+
+}  // namespace testing
+}  // namespace flutter
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
new file mode 100644
index 0000000000000..684b87357f40c
--- /dev/null
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -0,0 +1,58 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <windowsx.h>
+
+#include "flutter/fml/macros.h"
+#include "flutter/shell/platform/windows/win32_window.h"
+
+namespace flutter {
+namespace testing {
+
+class Win32WindowTest : public Win32Window {
+ public:
+  Win32WindowTest();
+  ~Win32WindowTest();
+
+  UINT GetDpi();
+
+  // |Win32Window|
+  void OnDpiScale(unsigned int dpi) override;
+
+  // |Win32Window|
+  void OnResize(unsigned int width, unsigned int height) override;
+
+  // |Win32Window|
+  void OnPointerMove(double x, double y) override;
+
+  // |Win32Window|
+  void OnPointerDown(double x, double y, UINT button) override;
+
+  // |Win32Window|
+  void OnPointerUp(double x, double y, UINT button) override;
+
+  // |Win32Window|
+  void OnPointerLeave() override;
+
+  // |Win32Window|
+  void OnChar(char32_t code_point) override;
+
+  // |Win32Window|
+  void OnKey(int key, int scancode, int action, int mods) override;
+
+  // |Win32Window|
+  void OnScroll(double delta_x, double delta_y) override;
+
+  // |Win32Window|
+  void OnClose();
+
+  // |Win32Window|
+  void OnFontChange() override;
+
+ private:
+  FML_DISALLOW_COPY_AND_ASSIGN(Win32WindowTest);
+};
+
+}  // namespace testing
+}  // namespace flutter
diff --git a/shell/platform/windows/win32_window_unittests.cc b/shell/platform/windows/win32_flutter_window_unittests.cc
similarity index 100%
rename from shell/platform/windows/win32_window_unittests.cc
rename to shell/platform/windows/win32_flutter_window_unittests.cc
diff --git a/shell/platform/windows/win32_window_unittest.cc b/shell/platform/windows/win32_window_unittest.cc
new file mode 100644
index 0000000000000..56f504bfaf50f
--- /dev/null
+++ b/shell/platform/windows/win32_window_unittest.cc
@@ -0,0 +1,14 @@
+#include "flutter/shell/platform/windows/testing/win32_window_unittest.h"
+
+#include "gtest/gtest.h"
+
+namespace flutter {
+namespace testing {
+
+TEST(Win32WindowTest, GetDpiAfterCreate) {
+  Win32WindowTest window;
+  ASSERT_TRUE(window.GetDpi() > 0);
+}
+
+}  // namespace testing
+}  // namespace flutter
diff --git a/testing/run_tests.py b/testing/run_tests.py
index cb11932eae934..931215d8bb60c 100755
--- a/testing/run_tests.py
+++ b/testing/run_tests.py
@@ -357,6 +357,7 @@ def main():
       default=False, help='Show extra dart snapshot logging.')
 
   args = parser.parse_args()
+  print args, '====='
 
   if args.type == 'all':
     types = ['engine', 'dart', 'benchmarks', 'java', 'font-subset']

From 3b1ffc5f2b3360fc1a17f9b2554692ffaaa0bf9e Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 14:23:17 -0800
Subject: [PATCH 15/38] Clean

---
 shell/platform/windows/BUILD.gn                            | 6 +++---
 .../client_wrapper/testing/stub_flutter_windows_api.cc     | 7 -------
 .../client_wrapper/testing/stub_flutter_windows_api.h      | 3 ---
 shell/platform/windows/testing/win32_window_test.cc        | 2 +-
 ...{win32_window_unittest.cc => win32_window_unittests.cc} | 2 +-
 5 files changed, 5 insertions(+), 15 deletions(-)
 rename shell/platform/windows/{win32_window_unittest.cc => win32_window_unittests.cc} (75%)

diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index 4be5ca2d0415c..b75a3179360eb 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -113,9 +113,9 @@ executable("flutter_windows_unittests") {
   sources = [
     "testing/win32_flutter_window_test.cc",
     "testing/win32_flutter_window_test.h",
-    "testing/win32_window_unittest.cc",
-    "testing/win32_window_unittest.h",
-    "win32_window_unittest.cc",
+    "testing/win32_window_test.cc",
+    "testing/win32_window_test.h",
+    "win32_window_unittests.cc",
     "win32_flutter_window_unittests.cc",
   ]
 
diff --git a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc
index b8c00111eda6e..07dfb8bd7bbbf 100644
--- a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc
+++ b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.cc
@@ -78,13 +78,6 @@ HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef controller) {
   return reinterpret_cast<HWND>(-1);
 }
 
-UINT FlutterDesktopGetDpiForHWND(HWND hwnd) {
-  if (s_stub_implementation) {
-    return s_stub_implementation->GetDpiForHWND();
-  }
-  return 0;
-}
-
 FlutterDesktopEngineRef FlutterDesktopRunEngine(const char* assets_path,
                                                 const char* icu_data_path,
                                                 const char** arguments,
diff --git a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h
index c54bcd400c6bc..0fd74c5b275f5 100644
--- a/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h
+++ b/shell/platform/windows/client_wrapper/testing/stub_flutter_windows_api.h
@@ -49,9 +49,6 @@ class StubFlutterWindowsApi {
   // Called for FlutterDesktopViewGetHWND.
   virtual HWND ViewGetHWND() { return reinterpret_cast<HWND>(1); }
 
-  // Called for FlutterDesktopGetDpiForHWND.
-  virtual UINT GetDpiForHWND() { return 1; }
-
   // Called for FlutterDesktopRunEngine.
   virtual FlutterDesktopEngineRef RunEngine(const char* assets_path,
                                             const char* icu_data_path,
diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
index bf651047290dd..ed889d8ea78b1 100644
--- a/shell/platform/windows/testing/win32_window_test.cc
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -1,4 +1,4 @@
-#include "flutter/shell/platform/windows/testing/win32_window_unittest.h"
+#include "flutter/shell/platform/windows/testing/win32_window_test.h"
 
 #include <iostream>
 
diff --git a/shell/platform/windows/win32_window_unittest.cc b/shell/platform/windows/win32_window_unittests.cc
similarity index 75%
rename from shell/platform/windows/win32_window_unittest.cc
rename to shell/platform/windows/win32_window_unittests.cc
index 56f504bfaf50f..38e62eda77eae 100644
--- a/shell/platform/windows/win32_window_unittest.cc
+++ b/shell/platform/windows/win32_window_unittests.cc
@@ -1,4 +1,4 @@
-#include "flutter/shell/platform/windows/testing/win32_window_unittest.h"
+#include "flutter/shell/platform/windows/testing/win32_window_test.h"
 
 #include "gtest/gtest.h"
 

From 31c39d23576e616df8a78827e8355e66bec221d3 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 14:40:56 -0800
Subject: [PATCH 16/38] Clean

---
 ci/licenses_golden/licenses_flutter                         | 3 ++-
 shell/platform/windows/dpi_utils.cc                         | 2 +-
 shell/platform/windows/testing/win32_flutter_window_test.cc | 1 -
 testing/run_tests.py                                        | 1 -
 4 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 964ae44d29eab..586168242bb42 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1121,11 +1121,12 @@ FILE: ../../../flutter/shell/platform/windows/text_input_plugin.cc
 FILE: ../../../flutter/shell/platform/windows/text_input_plugin.h
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.cc
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.h
+FILE: ../../../flutter/shell/platform/windows/win32_flutter_window_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.h
 FILE: ../../../flutter/shell/platform/windows/win32_window.cc
 FILE: ../../../flutter/shell/platform/windows/win32_window.h
-FILE: ../../../flutter/shell/platform/windows/win32_flutter_window_unittests.cc
+FILE: ../../../flutter/shell/platform/windows/win32_window_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/window_state.h
 FILE: ../../../flutter/shell/version/version.cc
 FILE: ../../../flutter/shell/version/version.h
diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 053ff4236cc8b..c318534804dff 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -27,7 +27,7 @@ class Win32DpiHelper {
 
   /// Returns the current DPI. Supports all DPI awareness modes, and is backward
   /// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI
-  /// for the nearest monitor is available. Otherwise, returns the system's DPI.
+  /// for the primary monitor. Otherwise, returns the system's DPI.
   UINT GetDpiForWindow(HWND);
 
   /// Returns the DPI of a given monitor. Defaults to 96 if the API is not
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.cc b/shell/platform/windows/testing/win32_flutter_window_test.cc
index cdb06ede12365..080262ae4bf88 100644
--- a/shell/platform/windows/testing/win32_flutter_window_test.cc
+++ b/shell/platform/windows/testing/win32_flutter_window_test.cc
@@ -1,5 +1,4 @@
 #include "flutter/shell/platform/windows/testing/win32_flutter_window_test.h"
-
 #include <iostream>
 
 namespace flutter {
diff --git a/testing/run_tests.py b/testing/run_tests.py
index 931215d8bb60c..cb11932eae934 100755
--- a/testing/run_tests.py
+++ b/testing/run_tests.py
@@ -357,7 +357,6 @@ def main():
       default=False, help='Show extra dart snapshot logging.')
 
   args = parser.parse_args()
-  print args, '====='
 
   if args.type == 'all':
     types = ['engine', 'dart', 'benchmarks', 'java', 'font-subset']

From fc9c47c97725e8c5dc2981cbb337f41400999b1f Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 15:20:42 -0800
Subject: [PATCH 17/38] Merge tests

---
 ci/licenses_golden/licenses_flutter           |  1 -
 shell/platform/windows/BUILD.gn               |  3 --
 .../testing/win32_flutter_window_test.cc      | 20 ------------
 .../testing/win32_flutter_window_test.h       | 31 -------------------
 .../windows/testing/win32_window_test.cc      | 10 +++++-
 .../windows/testing/win32_window_test.h       |  6 ++++
 .../windows/win32_flutter_window_unittests.cc | 22 -------------
 .../windows/win32_window_unittests.cc         | 20 ++++++++++--
 8 files changed, 33 insertions(+), 80 deletions(-)
 delete mode 100644 shell/platform/windows/testing/win32_flutter_window_test.cc
 delete mode 100644 shell/platform/windows/testing/win32_flutter_window_test.h
 delete mode 100644 shell/platform/windows/win32_flutter_window_unittests.cc

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 586168242bb42..0fb09282b57c3 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1121,7 +1121,6 @@ FILE: ../../../flutter/shell/platform/windows/text_input_plugin.cc
 FILE: ../../../flutter/shell/platform/windows/text_input_plugin.h
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.cc
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.h
-FILE: ../../../flutter/shell/platform/windows/win32_flutter_window_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.h
 FILE: ../../../flutter/shell/platform/windows/win32_window.cc
diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index b75a3179360eb..1d156979e5a65 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -111,12 +111,9 @@ executable("flutter_windows_unittests") {
   testonly = true
 
   sources = [
-    "testing/win32_flutter_window_test.cc",
-    "testing/win32_flutter_window_test.h",
     "testing/win32_window_test.cc",
     "testing/win32_window_test.h",
     "win32_window_unittests.cc",
-    "win32_flutter_window_unittests.cc",
   ]
 
   public_configs = [ "$flutter_root:config" ]
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.cc b/shell/platform/windows/testing/win32_flutter_window_test.cc
deleted file mode 100644
index 080262ae4bf88..0000000000000
--- a/shell/platform/windows/testing/win32_flutter_window_test.cc
+++ /dev/null
@@ -1,20 +0,0 @@
-#include "flutter/shell/platform/windows/testing/win32_flutter_window_test.h"
-#include <iostream>
-
-namespace flutter {
-namespace testing {
-
-Win32FlutterWindowTest::Win32FlutterWindowTest(int width, int height)
-    : Win32FlutterWindow(width, height){};
-
-Win32FlutterWindowTest::~Win32FlutterWindowTest() = default;
-
-void Win32FlutterWindowTest::OnFontChange() {
-  on_font_change_called_ = true;
-}
-
-bool Win32FlutterWindowTest::OnFontChangeWasCalled() {
-  return on_font_change_called_;
-}
-}  // namespace testing
-}  // namespace flutter
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.h b/shell/platform/windows/testing/win32_flutter_window_test.h
deleted file mode 100644
index 361a6960a5fc6..0000000000000
--- a/shell/platform/windows/testing/win32_flutter_window_test.h
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <windowsx.h>
-
-#include "flutter/fml/macros.h"
-#include "flutter/shell/platform/windows/win32_flutter_window.h"
-
-namespace flutter {
-namespace testing {
-
-class Win32FlutterWindowTest : public Win32FlutterWindow {
- public:
-  Win32FlutterWindowTest(int width, int height);
-
-  ~Win32FlutterWindowTest();
-
-  // |Win32Window|
-  void OnFontChange() override;
-
-  bool OnFontChangeWasCalled();
-
- private:
-  bool on_font_change_called_ = false;
-
-  FML_DISALLOW_COPY_AND_ASSIGN(Win32FlutterWindowTest);
-};
-
-}  // namespace testing
-}  // namespace flutter
diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
index ed889d8ea78b1..2eecafb586232 100644
--- a/shell/platform/windows/testing/win32_window_test.cc
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -31,11 +31,19 @@ void Win32WindowTest::OnScroll(double delta_x, double delta_y) {}
 
 void Win32WindowTest::OnClose() {}
 
-void Win32WindowTest::OnFontChange() {}
+void Win32WindowTest::OnFontChange() {
+  std::cerr << "Getting called ======\n";
+  on_font_change_called_ = true;
+}
 
 UINT Win32WindowTest::GetDpi() {
   return GetCurrentDPI();
 }
 
+bool Win32WindowTest::OnFontChangeWasCalled() {
+  std::cerr << "on font changed called====s\n";
+  return on_font_change_called_;
+}
+
 }  // namespace testing
 }  // namespace flutter
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index 684b87357f40c..6e815313bb4cf 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -15,8 +15,12 @@ class Win32WindowTest : public Win32Window {
   Win32WindowTest();
   ~Win32WindowTest();
 
+  // Wrapper for GetCurrentDPI() which is a protected method.
   UINT GetDpi();
 
+  // Returns a bool whether OnFontChange() was called.
+  bool OnFontChangeWasCalled();
+
   // |Win32Window|
   void OnDpiScale(unsigned int dpi) override;
 
@@ -51,6 +55,8 @@ class Win32WindowTest : public Win32Window {
   void OnFontChange() override;
 
  private:
+   bool on_font_change_called_ = false;
+
   FML_DISALLOW_COPY_AND_ASSIGN(Win32WindowTest);
 };
 
diff --git a/shell/platform/windows/win32_flutter_window_unittests.cc b/shell/platform/windows/win32_flutter_window_unittests.cc
deleted file mode 100644
index d04458492dff1..0000000000000
--- a/shell/platform/windows/win32_flutter_window_unittests.cc
+++ /dev/null
@@ -1,22 +0,0 @@
-#include "flutter/shell/platform/windows/testing/win32_flutter_window_test.h"
-#include "gtest/gtest.h"
-
-namespace flutter {
-namespace testing {
-
-TEST(Win32FlutterWindowTest, CreateDestroy) {
-  Win32FlutterWindowTest window(800, 600);
-  ASSERT_TRUE(TRUE);
-}
-
-TEST(Win32FlutterWindowTest, CanFontChange) {
-  Win32FlutterWindowTest window(800, 600);
-  HWND hwnd = window.GetWindowHandle();
-  LRESULT result = SendMessage(hwnd, WM_FONTCHANGE, NULL, NULL);
-  ASSERT_EQ(result, 0);
-  ASSERT_TRUE(window.OnFontChangeWasCalled());
-  ASSERT_TRUE(TRUE);
-}
-
-}  // namespace testing
-}  // namespace flutter
diff --git a/shell/platform/windows/win32_window_unittests.cc b/shell/platform/windows/win32_window_unittests.cc
index 38e62eda77eae..24b9d515d716c 100644
--- a/shell/platform/windows/win32_window_unittests.cc
+++ b/shell/platform/windows/win32_window_unittests.cc
@@ -1,14 +1,30 @@
 #include "flutter/shell/platform/windows/testing/win32_window_test.h"
-
 #include "gtest/gtest.h"
 
 namespace flutter {
 namespace testing {
 
+TEST(Win32WindowTest, CreateDestroy) {
+  Win32WindowTest window;
+  ASSERT_TRUE(TRUE);
+}
+
+TEST(Win32WindowTest, CanFontChange) {
+  Win32WindowTest window;
+  window.InitializeChild("FLUTTERVIEW", 10, 10);
+
+  HWND hwnd = window.GetWindowHandle();
+  LRESULT result = SendMessage(hwnd, WM_FONTCHANGE, NULL, NULL);
+  ASSERT_EQ(result, 0);
+  ASSERT_TRUE(window.OnFontChangeWasCalled());
+  ASSERT_TRUE(TRUE);
+
+  window.Destroy();
+}
+
 TEST(Win32WindowTest, GetDpiAfterCreate) {
   Win32WindowTest window;
   ASSERT_TRUE(window.GetDpi() > 0);
 }
-
 }  // namespace testing
 }  // namespace flutter

From 226581ecf453c5c4010af0144c70cd620faf851e Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 15:22:29 -0800
Subject: [PATCH 18/38] Comments and format

---
 shell/platform/windows/testing/win32_window_test.cc | 4 ----
 shell/platform/windows/testing/win32_window_test.h  | 2 +-
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
index 2eecafb586232..03b0d42a88d5e 100644
--- a/shell/platform/windows/testing/win32_window_test.cc
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -1,7 +1,5 @@
 #include "flutter/shell/platform/windows/testing/win32_window_test.h"
 
-#include <iostream>
-
 namespace flutter {
 namespace testing {
 
@@ -32,7 +30,6 @@ void Win32WindowTest::OnScroll(double delta_x, double delta_y) {}
 void Win32WindowTest::OnClose() {}
 
 void Win32WindowTest::OnFontChange() {
-  std::cerr << "Getting called ======\n";
   on_font_change_called_ = true;
 }
 
@@ -41,7 +38,6 @@ UINT Win32WindowTest::GetDpi() {
 }
 
 bool Win32WindowTest::OnFontChangeWasCalled() {
-  std::cerr << "on font changed called====s\n";
   return on_font_change_called_;
 }
 
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index 6e815313bb4cf..07f4fe841f777 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -55,7 +55,7 @@ class Win32WindowTest : public Win32Window {
   void OnFontChange() override;
 
  private:
-   bool on_font_change_called_ = false;
+  bool on_font_change_called_ = false;
 
   FML_DISALLOW_COPY_AND_ASSIGN(Win32WindowTest);
 };

From c9e38c8433dee6eee1ad69bc98e92520504ff62c Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 16:05:18 -0800
Subject: [PATCH 19/38] license

---
 ci/licenses_golden/licenses_flutter | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 0fb09282b57c3..a933c9d6b6f39 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1108,8 +1108,8 @@ FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flu
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/plugin_registrar_windows.h
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/plugin_registrar_windows_unittests.cc
-FILE: ../../../flutter/shell/platform/windows/dpi_utils.h
 FILE: ../../../flutter/shell/platform/windows/dpi_utils.cc
+FILE: ../../../flutter/shell/platform/windows/dpi_utils.h
 FILE: ../../../flutter/shell/platform/windows/flutter_windows.cc
 FILE: ../../../flutter/shell/platform/windows/key_event_handler.cc
 FILE: ../../../flutter/shell/platform/windows/key_event_handler.h

From 9e8ccfb754f8b3346620194540ec5e2b4e81140a Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Wed, 5 Feb 2020 22:36:17 -0800
Subject: [PATCH 20/38] Comments

---
 shell/platform/windows/testing/win32_window_test.h | 2 +-
 shell/platform/windows/win32_window.cc             | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index 07f4fe841f777..7b6f9f016f5cf 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -49,7 +49,7 @@ class Win32WindowTest : public Win32Window {
   void OnScroll(double delta_x, double delta_y) override;
 
   // |Win32Window|
-  void OnClose();
+  void OnClose() override;
 
   // |Win32Window|
   void OnFontChange() override;
diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index 773421981e4ad..bd8907573be30 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -9,7 +9,7 @@
 namespace flutter {
 
 Win32Window::Win32Window() {
-  // Calling GetDpiForHWND with no HNWD returns the DPI from the nearest
+  // Calling GetDpiForHWND with no HNWD returns the DPI from the primary
   // monitor, which is the best option as an initial DPI. If Per-Monitor V2 is
   // supported, |current_dpi_| should be updated in the WM_DPICHANGED message.
   current_dpi_ = GetDpiForHWND(nullptr);
@@ -81,7 +81,6 @@ LRESULT CALLBACK Win32Window::WndProc(HWND const window,
                      reinterpret_cast<LONG_PTR>(cs->lpCreateParams));
 
     auto that = static_cast<Win32Window*>(cs->lpCreateParams);
-
     that->window_handle_ = window;
   } else if (Win32Window* that = GetThisFromHandle(window)) {
     return that->MessageHandler(window, message, wparam, lparam);

From efa8fcc7907ea858088e61cdf7aa113e4d907720 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 6 Feb 2020 14:45:31 -0800
Subject: [PATCH 21/38] Virtual destructors

---
 .../testing/win32_flutter_window_test.cc      | 19 ++++++++++++
 .../testing/win32_flutter_window_test.h       | 31 +++++++++++++++++++
 .../platform/windows/win32_flutter_window.cc  |  8 ++---
 shell/platform/windows/win32_flutter_window.h | 11 +++----
 shell/platform/windows/win32_window.cc        |  5 ---
 shell/platform/windows/win32_window.h         |  8 ++---
 .../windows/win32_window_unittests.cc         |  3 --
 7 files changed, 60 insertions(+), 25 deletions(-)
 create mode 100644 shell/platform/windows/testing/win32_flutter_window_test.cc
 create mode 100644 shell/platform/windows/testing/win32_flutter_window_test.h

diff --git a/shell/platform/windows/testing/win32_flutter_window_test.cc b/shell/platform/windows/testing/win32_flutter_window_test.cc
new file mode 100644
index 0000000000000..bae1d9cd8d5b3
--- /dev/null
+++ b/shell/platform/windows/testing/win32_flutter_window_test.cc
@@ -0,0 +1,19 @@
+#include "flutter/shell/platform/windows/testing/win32_flutter_window_test.h"
+
+namespace flutter {
+namespace testing {
+
+Win32FlutterWindowTest::Win32FlutterWindowTest(int width, int height)
+    : Win32FlutterWindow(width, height){};
+
+Win32FlutterWindowTest::~Win32FlutterWindowTest() = default;
+
+void Win32FlutterWindowTest::OnFontChange() {
+  on_font_change_called_ = true;
+}
+
+bool Win32FlutterWindowTest::OnFontChangeWasCalled() {
+  return on_font_change_called_;
+}
+}  // namespace testing
+}  // namespace flutter
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.h b/shell/platform/windows/testing/win32_flutter_window_test.h
new file mode 100644
index 0000000000000..24a53f7c529c6
--- /dev/null
+++ b/shell/platform/windows/testing/win32_flutter_window_test.h
@@ -0,0 +1,31 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <windowsx.h>
+
+#include "flutter/fml/macros.h"
+#include "flutter/shell/platform/windows/win32_flutter_window.h"
+
+namespace flutter {
+namespace testing {
+
+class Win32FlutterWindowTest : public Win32FlutterWindow {
+ public:
+  Win32FlutterWindowTest(int width, int height);
+
+  virtual ~Win32FlutterWindowTest();
+
+  // |Win32Window|
+  void OnFontChange() override;
+
+  bool OnFontChangeWasCalled();
+
+ private:
+  bool on_font_change_called_ = false;
+
+  FML_DISALLOW_COPY_AND_ASSIGN(Win32FlutterWindowTest);
+};
+
+}  // namespace testing
+}  // namespace flutter
diff --git a/shell/platform/windows/win32_flutter_window.cc b/shell/platform/windows/win32_flutter_window.cc
index b5d8de160a60d..a3c7fcd11c91e 100644
--- a/shell/platform/windows/win32_flutter_window.cc
+++ b/shell/platform/windows/win32_flutter_window.cc
@@ -4,7 +4,7 @@
 
 namespace flutter {
 
-// the Windows DPI system is based on this
+// The Windows DPI system is based on this
 // constant for machines running at 100% scaling.
 constexpr int base_dpi = 96;
 
@@ -15,7 +15,6 @@ Win32FlutterWindow::Win32FlutterWindow(int width, int height) {
 
 Win32FlutterWindow::~Win32FlutterWindow() {
   DestroyRenderSurface();
-  Win32Window::Destroy();
 }
 
 FlutterDesktopViewControllerRef Win32FlutterWindow::CreateWin32FlutterWindow(
@@ -177,9 +176,7 @@ void Win32FlutterWindow::OnScroll(double delta_x, double delta_y) {
   }
 }
 
-void Win32FlutterWindow::OnClose() {
-  messageloop_running_ = false;
-}
+void Win32FlutterWindow::OnClose() {}
 
 void Win32FlutterWindow::OnFontChange() {
   if (engine_ == nullptr) {
@@ -365,5 +362,4 @@ void Win32FlutterWindow::DestroyRenderSurface() {
   }
   render_surface = EGL_NO_SURFACE;
 }
-
 }  // namespace flutter
diff --git a/shell/platform/windows/win32_flutter_window.h b/shell/platform/windows/win32_flutter_window.h
index 4d08b4117dabf..6611d1493d4cb 100644
--- a/shell/platform/windows/win32_flutter_window.h
+++ b/shell/platform/windows/win32_flutter_window.h
@@ -33,7 +33,7 @@ class Win32FlutterWindow : public Win32Window {
   // Create flutter Window for use as child window
   Win32FlutterWindow(int width, int height);
 
-  ~Win32FlutterWindow();
+  virtual ~Win32FlutterWindow();
 
   static FlutterDesktopViewControllerRef
   Win32FlutterWindow::CreateWin32FlutterWindow(int width, int height);
@@ -85,9 +85,6 @@ class Win32FlutterWindow : public Win32Window {
   // Create a surface for Flutter engine to render into.
   void CreateRenderSurface();
 
-  // Destroy current rendering surface if one has been allocated.
-  void DestroyRenderSurface();
-
   // Callbacks for clearing context, settings context and swapping buffers.
   bool ClearContext();
   bool MakeCurrent();
@@ -99,6 +96,9 @@ class Win32FlutterWindow : public Win32Window {
   void SendWindowMetrics();
 
  private:
+  // Destroy current rendering surface if one has been allocated.
+  void DestroyRenderSurface();
+
   // Reports a mouse movement to Flutter engine.
   void SendPointerMove(double x, double y);
 
@@ -174,9 +174,6 @@ class Win32FlutterWindow : public Win32Window {
 
   // should we forword input messages or not
   bool process_events_ = false;
-
-  // flag indicating if the message loop should be running
-  bool messageloop_running_ = false;
 };
 
 }  // namespace flutter
diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index bd8907573be30..1be6de36b56e5 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -118,10 +118,6 @@ Win32Window::MessageHandler(HWND hwnd,
       case kWmDpiChangedBeforeParent:
         return HandleDpiChange(window_handle_, wparam, lparam, false);
         break;
-      case WM_DESTROY:
-        window->OnClose();
-        return 0;
-        break;
       case WM_SIZE:
         width = LOWORD(lparam);
         height = HIWORD(lparam);
@@ -254,7 +250,6 @@ void Win32Window::Destroy() {
     DestroyWindow(window_handle_);
     window_handle_ = nullptr;
   }
-
   UnregisterClass(window_class_name_.c_str(), nullptr);
 }
 
diff --git a/shell/platform/windows/win32_window.h b/shell/platform/windows/win32_window.h
index b0a1e10b3fa3a..98caacbb1e37c 100644
--- a/shell/platform/windows/win32_window.h
+++ b/shell/platform/windows/win32_window.h
@@ -35,7 +35,7 @@ struct MouseState {
 class Win32Window {
  public:
   Win32Window();
-  ~Win32Window();
+  virtual ~Win32Window();
 
   // Initializes as a child window with size using |width| and |height| and
   // |title| to identify the windowclass.  Does not show window, window must be
@@ -44,9 +44,6 @@ class Win32Window {
                        unsigned int width,
                        unsigned int height);
 
-  // Release OS resources asociated with window.
-  virtual void Destroy();
-
   HWND GetWindowHandle();
 
  protected:
@@ -148,6 +145,9 @@ class Win32Window {
   void SetMouseButtons(uint64_t buttons) { mouse_state_.buttons = buttons; }
 
  private:
+  // Release OS resources asociated with window.
+  void Destroy();
+
   // Activates tracking for a "mouse leave" event.
   void TrackMouseLeaveEvent(HWND hwnd);
 
diff --git a/shell/platform/windows/win32_window_unittests.cc b/shell/platform/windows/win32_window_unittests.cc
index 24b9d515d716c..576fe12349201 100644
--- a/shell/platform/windows/win32_window_unittests.cc
+++ b/shell/platform/windows/win32_window_unittests.cc
@@ -17,9 +17,6 @@ TEST(Win32WindowTest, CanFontChange) {
   LRESULT result = SendMessage(hwnd, WM_FONTCHANGE, NULL, NULL);
   ASSERT_EQ(result, 0);
   ASSERT_TRUE(window.OnFontChangeWasCalled());
-  ASSERT_TRUE(TRUE);
-
-  window.Destroy();
 }
 
 TEST(Win32WindowTest, GetDpiAfterCreate) {

From 9dfbad6c439590e8ab5d40b3da944c9572ba427c Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 6 Feb 2020 15:15:43 -0800
Subject: [PATCH 22/38] Move tests

---
 shell/platform/windows/BUILD.gn               |  3 +++
 .../windows/testing/win32_window_test.cc      | 10 ---------
 .../windows/testing/win32_window_test.h       |  5 -----
 .../windows/win32_flutter_window_unittests.cc | 21 +++++++++++++++++++
 .../windows/win32_window_unittests.cc         | 10 ---------
 5 files changed, 24 insertions(+), 25 deletions(-)
 create mode 100644 shell/platform/windows/win32_flutter_window_unittests.cc

diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index 1d156979e5a65..eacc7aedcc08d 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -111,8 +111,11 @@ executable("flutter_windows_unittests") {
   testonly = true
 
   sources = [
+    "testing/win32_flutter_window_test.cc",
+    "testing/win32_flutter_window_test.h",
     "testing/win32_window_test.cc",
     "testing/win32_window_test.h",
+    "win32_flutter_window_unittests.cc",
     "win32_window_unittests.cc",
   ]
 
diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
index 03b0d42a88d5e..65e55b0dd6e92 100644
--- a/shell/platform/windows/testing/win32_window_test.cc
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -9,8 +9,6 @@ Win32WindowTest::~Win32WindowTest() = default;
 
 void Win32WindowTest::OnDpiScale(unsigned int dpi){};
 
-// When DesktopWindow notifies that a WM_Size message has come in
-// lets FlutterEngine know about the new size.
 void Win32WindowTest::OnResize(unsigned int width, unsigned int height) {}
 
 void Win32WindowTest::OnPointerMove(double x, double y) {}
@@ -29,17 +27,9 @@ void Win32WindowTest::OnScroll(double delta_x, double delta_y) {}
 
 void Win32WindowTest::OnClose() {}
 
-void Win32WindowTest::OnFontChange() {
-  on_font_change_called_ = true;
-}
-
 UINT Win32WindowTest::GetDpi() {
   return GetCurrentDPI();
 }
 
-bool Win32WindowTest::OnFontChangeWasCalled() {
-  return on_font_change_called_;
-}
-
 }  // namespace testing
 }  // namespace flutter
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index 7b6f9f016f5cf..925f7178574e6 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -18,9 +18,6 @@ class Win32WindowTest : public Win32Window {
   // Wrapper for GetCurrentDPI() which is a protected method.
   UINT GetDpi();
 
-  // Returns a bool whether OnFontChange() was called.
-  bool OnFontChangeWasCalled();
-
   // |Win32Window|
   void OnDpiScale(unsigned int dpi) override;
 
@@ -55,8 +52,6 @@ class Win32WindowTest : public Win32Window {
   void OnFontChange() override;
 
  private:
-  bool on_font_change_called_ = false;
-
   FML_DISALLOW_COPY_AND_ASSIGN(Win32WindowTest);
 };
 
diff --git a/shell/platform/windows/win32_flutter_window_unittests.cc b/shell/platform/windows/win32_flutter_window_unittests.cc
new file mode 100644
index 0000000000000..dece5a280f807
--- /dev/null
+++ b/shell/platform/windows/win32_flutter_window_unittests.cc
@@ -0,0 +1,21 @@
+#include "flutter/shell/platform/windows/testing/win32_flutter_window_test.h"
+#include "gtest/gtest.h"
+
+namespace flutter {
+namespace testing {
+
+TEST(Win32FlutterWindowTest, CreateDestroy) {
+  Win32FlutterWindowTest window(800, 600);
+  ASSERT_TRUE(TRUE);
+}
+
+TEST(Win32FlutterWindowTest, CanFontChange) {
+  Win32FlutterWindowTest window(800, 600);
+  HWND hwnd = window.GetWindowHandle();
+  LRESULT result = SendMessage(hwnd, WM_FONTCHANGE, NULL, NULL);
+  ASSERT_EQ(result, 0);
+  ASSERT_TRUE(window.OnFontChangeWasCalled());
+}
+
+}  // namespace testing
+}  // namespace flutter
diff --git a/shell/platform/windows/win32_window_unittests.cc b/shell/platform/windows/win32_window_unittests.cc
index 576fe12349201..978bec4fc6462 100644
--- a/shell/platform/windows/win32_window_unittests.cc
+++ b/shell/platform/windows/win32_window_unittests.cc
@@ -9,16 +9,6 @@ TEST(Win32WindowTest, CreateDestroy) {
   ASSERT_TRUE(TRUE);
 }
 
-TEST(Win32WindowTest, CanFontChange) {
-  Win32WindowTest window;
-  window.InitializeChild("FLUTTERVIEW", 10, 10);
-
-  HWND hwnd = window.GetWindowHandle();
-  LRESULT result = SendMessage(hwnd, WM_FONTCHANGE, NULL, NULL);
-  ASSERT_EQ(result, 0);
-  ASSERT_TRUE(window.OnFontChangeWasCalled());
-}
-
 TEST(Win32WindowTest, GetDpiAfterCreate) {
   Win32WindowTest window;
   ASSERT_TRUE(window.GetDpi() > 0);

From 6e16a110d507fca7cee71b16c1d6710497ed49d8 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 6 Feb 2020 15:42:42 -0800
Subject: [PATCH 23/38] Add on font change

---
 shell/platform/windows/testing/win32_window_test.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
index 65e55b0dd6e92..881694fb5afa4 100644
--- a/shell/platform/windows/testing/win32_window_test.cc
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -27,6 +27,8 @@ void Win32WindowTest::OnScroll(double delta_x, double delta_y) {}
 
 void Win32WindowTest::OnClose() {}
 
+void Win32WindowTest::OnFontChange() {}
+
 UINT Win32WindowTest::GetDpi() {
   return GetCurrentDPI();
 }

From a4144e73990b71837bf3b437b4df38e701d904ac Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 6 Feb 2020 16:03:48 -0800
Subject: [PATCH 24/38] Remove onclose

---
 shell/platform/windows/testing/win32_window_test.cc | 2 --
 shell/platform/windows/testing/win32_window_test.h  | 3 ---
 shell/platform/windows/win32_flutter_window.cc      | 2 --
 shell/platform/windows/win32_flutter_window.h       | 3 ---
 shell/platform/windows/win32_window.h               | 3 ---
 5 files changed, 13 deletions(-)

diff --git a/shell/platform/windows/testing/win32_window_test.cc b/shell/platform/windows/testing/win32_window_test.cc
index 881694fb5afa4..13a70e039647c 100644
--- a/shell/platform/windows/testing/win32_window_test.cc
+++ b/shell/platform/windows/testing/win32_window_test.cc
@@ -25,8 +25,6 @@ void Win32WindowTest::OnKey(int key, int scancode, int action, int mods) {}
 
 void Win32WindowTest::OnScroll(double delta_x, double delta_y) {}
 
-void Win32WindowTest::OnClose() {}
-
 void Win32WindowTest::OnFontChange() {}
 
 UINT Win32WindowTest::GetDpi() {
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index 925f7178574e6..c1a715806ba19 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -45,9 +45,6 @@ class Win32WindowTest : public Win32Window {
   // |Win32Window|
   void OnScroll(double delta_x, double delta_y) override;
 
-  // |Win32Window|
-  void OnClose() override;
-
   // |Win32Window|
   void OnFontChange() override;
 
diff --git a/shell/platform/windows/win32_flutter_window.cc b/shell/platform/windows/win32_flutter_window.cc
index a3c7fcd11c91e..803732a20754f 100644
--- a/shell/platform/windows/win32_flutter_window.cc
+++ b/shell/platform/windows/win32_flutter_window.cc
@@ -176,8 +176,6 @@ void Win32FlutterWindow::OnScroll(double delta_x, double delta_y) {
   }
 }
 
-void Win32FlutterWindow::OnClose() {}
-
 void Win32FlutterWindow::OnFontChange() {
   if (engine_ == nullptr) {
     return;
diff --git a/shell/platform/windows/win32_flutter_window.h b/shell/platform/windows/win32_flutter_window.h
index 6611d1493d4cb..5e43ca4f34912 100644
--- a/shell/platform/windows/win32_flutter_window.h
+++ b/shell/platform/windows/win32_flutter_window.h
@@ -65,9 +65,6 @@ class Win32FlutterWindow : public Win32Window {
   // |Win32Window|
   void OnScroll(double delta_x, double delta_y) override;
 
-  // |Win32Window|
-  void OnClose();
-
   // |Win32Window|
   void OnFontChange() override;
 
diff --git a/shell/platform/windows/win32_window.h b/shell/platform/windows/win32_window.h
index 98caacbb1e37c..dfb5928048168 100644
--- a/shell/platform/windows/win32_window.h
+++ b/shell/platform/windows/win32_window.h
@@ -111,9 +111,6 @@ class Win32Window {
   // Called when mouse scrollwheel input occurs.
   virtual void OnScroll(double delta_x, double delta_y) = 0;
 
-  // Called when the user closes the Windows.
-  virtual void OnClose() = 0;
-
   // Called when the system font change.
   virtual void OnFontChange() = 0;
 

From d693ebb44b76eee4a38a3570136090472c339e22 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 6 Feb 2020 16:28:06 -0800
Subject: [PATCH 25/38] Remove dpi changed and primary monitor change

---
 shell/platform/windows/win32_window.cc | 52 +++++---------------------
 1 file changed, 9 insertions(+), 43 deletions(-)

diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index 1be6de36b56e5..d379e18940f2a 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -9,10 +9,12 @@
 namespace flutter {
 
 Win32Window::Win32Window() {
-  // Calling GetDpiForHWND with no HNWD returns the DPI from the primary
-  // monitor, which is the best option as an initial DPI. If Per-Monitor V2 is
-  // supported, |current_dpi_| should be updated in the WM_DPICHANGED message.
-  current_dpi_ = GetDpiForHWND(nullptr);
+  // Get the DPI of the primary monitor as the initial DPI. If Per-Monitor V2 is
+  // supported, |current_dpi_| should be updated in the
+  // kWmDpiChangedBeforeParent message.
+  const POINT target_point = {static_cast<LONG>(0), static_cast<LONG>(0)};
+  HMONITOR monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
+  current_dpi_ = GetDpiForMonitor(monitor);
 }
 
 Win32Window::~Win32Window() {
@@ -112,12 +114,10 @@ Win32Window::MessageHandler(HWND hwnd,
   UINT button_pressed = 0;
   if (window != nullptr) {
     switch (message) {
-      case WM_DPICHANGED:
-        return HandleDpiChange(window_handle_, wparam, lparam, true);
-        break;
       case kWmDpiChangedBeforeParent:
-        return HandleDpiChange(window_handle_, wparam, lparam, false);
-        break;
+        current_dpi_ = GetDpiForHWND(window_handle_);
+        window->OnDpiScale(current_dpi_);
+        return 0;
       case WM_SIZE:
         width = LOWORD(lparam);
         height = HIWORD(lparam);
@@ -253,40 +253,6 @@ void Win32Window::Destroy() {
   UnregisterClass(window_class_name_.c_str(), nullptr);
 }
 
-// DPI Change handler. on WM_DPICHANGE resize the window
-LRESULT
-Win32Window::HandleDpiChange(HWND hwnd,
-                             WPARAM wparam,
-                             LPARAM lparam,
-                             bool toplevel) {
-  if (hwnd != nullptr) {
-    auto window =
-        reinterpret_cast<Win32Window*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
-
-    UINT uDpi = HIWORD(wparam);
-
-    // The DPI is only passed for DPI change messages on top level windows,
-    // hence call function to get DPI if needed.
-    if (uDpi == 0) {
-      uDpi = GetDpiForHWND(hwnd);
-    }
-    current_dpi_ = uDpi;
-    window->OnDpiScale(uDpi);
-
-    if (toplevel) {
-      // Resize the window only for toplevel windows which have a suggested
-      // size.
-      auto lprcNewScale = reinterpret_cast<RECT*>(lparam);
-      LONG newWidth = lprcNewScale->right - lprcNewScale->left;
-      LONG newHeight = lprcNewScale->bottom - lprcNewScale->top;
-
-      SetWindowPos(hwnd, nullptr, lprcNewScale->left, lprcNewScale->top,
-                   newWidth, newHeight, SWP_NOZORDER | SWP_NOACTIVATE);
-    }
-  }
-  return 0;
-}
-
 void Win32Window::HandleResize(UINT width, UINT height) {
   current_width_ = width;
   current_height_ = height;

From 589923751ecd9d9ab631c9f9615ab23435a48a0c Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Thu, 6 Feb 2020 17:31:27 -0800
Subject: [PATCH 26/38] Fix

---
 shell/platform/windows/win32_window_unittests.cc | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/shell/platform/windows/win32_window_unittests.cc b/shell/platform/windows/win32_window_unittests.cc
index 812643c3f6a0c..0adc0b0388389 100644
--- a/shell/platform/windows/win32_window_unittests.cc
+++ b/shell/platform/windows/win32_window_unittests.cc
@@ -9,18 +9,10 @@ TEST(Win32WindowTest, CreateDestroy) {
   ASSERT_TRUE(TRUE);
 }
 
-<<<<<<< HEAD
 TEST(Win32WindowTest, GetDpiAfterCreate) {
   Win32WindowTest window;
   ASSERT_TRUE(window.GetDpi() > 0);
-=======
-TEST(Win32FlutterWindowTest, CanFontChange) {
-  Win32FlutterWindowTest window(800, 600);
-  HWND hwnd = window.GetWindowHandle();
-  LRESULT result = SendMessage(hwnd, WM_FONTCHANGE, NULL, NULL);
-  ASSERT_EQ(result, 0);
-  ASSERT_TRUE(window.OnFontChangeWasCalled());
->>>>>>> master
 }
+
 }  // namespace testing
 }  // namespace flutter

From f4a225a28fd32dc86d946c61eab157a3b3705b08 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 7 Feb 2020 08:41:58 -0800
Subject: [PATCH 27/38] monitor type enum

---
 shell/platform/windows/dpi_utils.cc | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index c318534804dff..33104e36a4090 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -1,13 +1,16 @@
 #include "dpi_utils.h"
 
-#include <ShellScalingApi.h>
-
 namespace flutter {
 
 namespace {
 
 constexpr UINT kDefaultDpi = 96;
 
+// This is the MDT_EFFECTIVE_DPI value from MONITOR_DPI_TYPE, an enum declared
+// in ShellScalingApi.h. Replicating here to avoid importing the library
+// directly.
+constexpr UINT kEffectiveDpiMonitorType = 0;
+
 template <typename T>
 
 /// Retrieves a function |name| from a given |comBaseModule| into |outProc|.
@@ -37,7 +40,7 @@ class Win32DpiHelper {
  private:
   using GetDpiForWindow_ = UINT __stdcall(HWND);
   using GetDpiForMonitor_ = HRESULT __stdcall(HMONITOR hmonitor,
-                                              MONITOR_DPI_TYPE dpiType,
+                                              UINT dpiType,
                                               UINT* dpiX,
                                               UINT* dpiY);
   using MonitorFromWindow_ = HMONITOR __stdcall(HWND hwnd, DWORD dwFlags);
@@ -101,7 +104,7 @@ UINT Win32DpiHelper::GetDpiForMonitor(HMONITOR monitor) {
   if (dpi_for_monitor_supported_) {
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
-        get_dpi_for_monitor_(monitor, MDT_EFFECTIVE_DPI, &dpi_x, &dpi_y);
+        get_dpi_for_monitor_(monitor, kEffectiveDpiMonitorType, &dpi_x, &dpi_y);
     return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
   }
   return kDefaultDpi;

From 93c1aebe31b60f1869c8410e98bb76bc4e61d38a Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 7 Feb 2020 08:48:56 -0800
Subject: [PATCH 28/38] Use MonitorFromWindow

---
 shell/platform/windows/dpi_utils.cc | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 33104e36a4090..d775844aa5c90 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -43,12 +43,10 @@ class Win32DpiHelper {
                                               UINT dpiType,
                                               UINT* dpiX,
                                               UINT* dpiY);
-  using MonitorFromWindow_ = HMONITOR __stdcall(HWND hwnd, DWORD dwFlags);
   using EnableNonClientDpiScaling_ = BOOL __stdcall(HWND hwnd);
 
   GetDpiForWindow_* get_dpi_for_window_ = nullptr;
   GetDpiForMonitor_* get_dpi_for_monitor_ = nullptr;
-  MonitorFromWindow_* monitor_from_window_ = nullptr;
   EnableNonClientDpiScaling_* enable_non_client_dpi_scaling_ = nullptr;
 
   HMODULE user32_module_ = nullptr;
@@ -66,11 +64,8 @@ Win32DpiHelper::Win32DpiHelper() {
 
   dpi_for_window_supported_ = (AssignProcAddress(
       user32_module_, "GetDpiForWindow", get_dpi_for_window_));
-  dpi_for_monitor_supported_ =
-      (AssignProcAddress(shlib_module_, "GetDpiForMonitor",
-                         get_dpi_for_monitor_) &&
-       AssignProcAddress(user32_module_, "MonitorFromWindow",
-                         monitor_from_window_));
+  dpi_for_monitor_supported_ = AssignProcAddress(
+      shlib_module_, "GetDpiForMonitor", get_dpi_for_monitor_);
 }
 
 Win32DpiHelper::~Win32DpiHelper() {
@@ -91,7 +86,7 @@ UINT Win32DpiHelper::GetDpiForWindow(HWND hwnd) {
   }
 
   if (dpi_for_monitor_supported_) {
-    HMONITOR monitor = monitor_from_window_(hwnd, MONITOR_DEFAULTTOPRIMARY);
+    HMONITOR monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTOPRIMARY);
     return GetDpiForMonitor(monitor);
   }
   HDC hdc = GetDC(hwnd);

From 688580cb3764ed8b0b0fee4b80b482f474b51532 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 7 Feb 2020 08:56:20 -0800
Subject: [PATCH 29/38] space

---
 shell/platform/windows/win32_window.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index d379e18940f2a..626df9ce9dc34 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -250,6 +250,7 @@ void Win32Window::Destroy() {
     DestroyWindow(window_handle_);
     window_handle_ = nullptr;
   }
+
   UnregisterClass(window_class_name_.c_str(), nullptr);
 }
 

From 838a9c2721d1c5611535ecc400e4e57f42a8dea0 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 7 Feb 2020 09:40:17 -0800
Subject: [PATCH 30/38] Default to primary correctly

---
 shell/platform/windows/dpi_utils.cc | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index d775844aa5c90..b0074f8a62d8a 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -86,7 +86,13 @@ UINT Win32DpiHelper::GetDpiForWindow(HWND hwnd) {
   }
 
   if (dpi_for_monitor_supported_) {
-    HMONITOR monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTOPRIMARY);
+    HMONITOR monitor;
+    if (hwnd == nullptr) {
+      const POINT target_point = {static_cast<LONG>(0), static_cast<LONG>(0)};
+      monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
+    } else {
+      monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTOPRIMARY);
+    }
     return GetDpiForMonitor(monitor);
   }
   HDC hdc = GetDC(hwnd);

From 2a98f8c9e3969ad227a47719ee5569fd1410dea6 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Fri, 7 Feb 2020 10:41:34 -0800
Subject: [PATCH 31/38] License

---
 ci/licenses_golden/licenses_flutter | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 46781e3ed3507..da25e74f8e907 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1129,6 +1129,7 @@ FILE: ../../../flutter/shell/platform/windows/text_input_plugin.cc
 FILE: ../../../flutter/shell/platform/windows/text_input_plugin.h
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.cc
 FILE: ../../../flutter/shell/platform/windows/win32_flutter_window.h
+FILE: ../../../flutter/shell/platform/windows/win32_flutter_window_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.cc
 FILE: ../../../flutter/shell/platform/windows/win32_task_runner.h
 FILE: ../../../flutter/shell/platform/windows/win32_window.cc

From 4ba92efac0674cef6bd29fc039617523f9a16d83 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 10 Feb 2020 13:43:28 -0800
Subject: [PATCH 32/38] Most comments

---
 shell/platform/windows/dpi_utils.cc           | 22 +++++++++----------
 shell/platform/windows/dpi_utils.h            |  7 +++---
 .../testing/win32_flutter_window_test.h       |  1 +
 .../windows/testing/win32_window_test.h       |  2 ++
 shell/platform/windows/win32_window.cc        |  4 +---
 5 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index b0074f8a62d8a..d54255d07b676 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -56,16 +56,14 @@ class Win32DpiHelper {
 };
 
 Win32DpiHelper::Win32DpiHelper() {
-  user32_module_ = LoadLibraryA("User32.dll");
-  shlib_module_ = LoadLibraryA("Shcore.dll");
-  if (shlib_module_ == nullptr && user32_module_ == nullptr) {
-    return;
+  if ((user32_module_ = LoadLibraryA("User32.dll")) != nullptr) {
+    dpi_for_window_supported_ = (AssignProcAddress(
+        user32_module_, "GetDpiForWindow", get_dpi_for_window_));
+  }
+  if ((shlib_module_ = LoadLibraryA("Shcore.dll")) != nullptr) {
+    dpi_for_monitor_supported_ = AssignProcAddress(
+        shlib_module_, "GetDpiForMonitor", get_dpi_for_monitor_);
   }
-
-  dpi_for_window_supported_ = (AssignProcAddress(
-      user32_module_, "GetDpiForWindow", get_dpi_for_window_));
-  dpi_for_monitor_supported_ = AssignProcAddress(
-      shlib_module_, "GetDpiForMonitor", get_dpi_for_monitor_);
 }
 
 Win32DpiHelper::~Win32DpiHelper() {
@@ -88,7 +86,7 @@ UINT Win32DpiHelper::GetDpiForWindow(HWND hwnd) {
   if (dpi_for_monitor_supported_) {
     HMONITOR monitor;
     if (hwnd == nullptr) {
-      const POINT target_point = {static_cast<LONG>(0), static_cast<LONG>(0)};
+      const POINT target_point = {0, 0};
       monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
     } else {
       monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTOPRIMARY);
@@ -106,7 +104,9 @@ UINT Win32DpiHelper::GetDpiForMonitor(HMONITOR monitor) {
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
         get_dpi_for_monitor_(monitor, kEffectiveDpiMonitorType, &dpi_x, &dpi_y);
-    return SUCCEEDED(result) ? dpi_x : kDefaultDpi;
+    if (SUCCEEDED(result)) {
+      return dpi_x;
+    }
   }
   return kDefaultDpi;
 }
diff --git a/shell/platform/windows/dpi_utils.h b/shell/platform/windows/dpi_utils.h
index 3895a2f2454be..1c14994b61235 100644
--- a/shell/platform/windows/dpi_utils.h
+++ b/shell/platform/windows/dpi_utils.h
@@ -9,9 +9,10 @@
 
 namespace flutter {
 
-/// Returns the current DPI. Supports all DPI awareness modes, and is backward
-/// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI for
-/// the primary monitor. Otherwise, returns the system's DPI.
+/// Returns the DPI for |hwnd|. Supports all DPI awareness modes, and is
+/// backward compatible down to Windows Vista. If |hwnd| is nullptr, returns the
+/// DPI for the primary monitor. If Per-Monitor DPI awareness is not available,
+/// returns the system's DPI.
 UINT GetDpiForHWND(HWND hwnd);
 
 /// Returns the DPI of a given monitor. Defaults to 96 if the API is not
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.h b/shell/platform/windows/testing/win32_flutter_window_test.h
index 24a53f7c529c6..98ee519def32b 100644
--- a/shell/platform/windows/testing/win32_flutter_window_test.h
+++ b/shell/platform/windows/testing/win32_flutter_window_test.h
@@ -10,6 +10,7 @@
 namespace flutter {
 namespace testing {
 
+/// Test class for Win32FlutterWindow.
 class Win32FlutterWindowTest : public Win32FlutterWindow {
  public:
   Win32FlutterWindowTest(int width, int height);
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index c1a715806ba19..4bb310e036b2a 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -10,6 +10,8 @@
 namespace flutter {
 namespace testing {
 
+/// Test class for the Win32Window base class. Used to access protected methods
+/// for testing.
 class Win32WindowTest : public Win32Window {
  public:
   Win32WindowTest();
diff --git a/shell/platform/windows/win32_window.cc b/shell/platform/windows/win32_window.cc
index 626df9ce9dc34..0abafb562fbf1 100644
--- a/shell/platform/windows/win32_window.cc
+++ b/shell/platform/windows/win32_window.cc
@@ -12,9 +12,7 @@ Win32Window::Win32Window() {
   // Get the DPI of the primary monitor as the initial DPI. If Per-Monitor V2 is
   // supported, |current_dpi_| should be updated in the
   // kWmDpiChangedBeforeParent message.
-  const POINT target_point = {static_cast<LONG>(0), static_cast<LONG>(0)};
-  HMONITOR monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
-  current_dpi_ = GetDpiForMonitor(monitor);
+  current_dpi_ = GetDpiForHWND(nullptr);
 }
 
 Win32Window::~Win32Window() {

From 57c11aa7dc6ff4dfa6ac7d9f2bcb9423305fdf1b Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 10 Feb 2020 13:46:12 -0800
Subject: [PATCH 33/38] Comment

---
 shell/platform/windows/dpi_utils.cc | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index d54255d07b676..42b1ed0372ddc 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -28,9 +28,10 @@ class Win32DpiHelper {
 
   ~Win32DpiHelper();
 
-  /// Returns the current DPI. Supports all DPI awareness modes, and is backward
-  /// compatible down to Windows Vista. If |hwnd| is nullptr, returns the DPI
-  /// for the primary monitor. Otherwise, returns the system's DPI.
+  /// Returns the DPI for |hwnd|. Supports all DPI awareness modes, and is
+  /// backward compatible down to Windows Vista. If |hwnd| is nullptr, returns
+  /// the DPI for the primary monitor. If Per-Monitor DPI awareness is not
+  /// available, returns the system's DPI.
   UINT GetDpiForWindow(HWND);
 
   /// Returns the DPI of a given monitor. Defaults to 96 if the API is not

From 20dcea8f3ae0bc92f28d40e675c60700df5ab763 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 10 Feb 2020 14:34:02 -0800
Subject: [PATCH 34/38] Add test

---
 ci/licenses_golden/licenses_flutter | 1 +
 shell/platform/windows/BUILD.gn     | 1 +
 2 files changed, 2 insertions(+)

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index da25e74f8e907..bbd6348acf5e8 100644
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -1118,6 +1118,7 @@ FILE: ../../../flutter/shell/platform/windows/client_wrapper/include/flutter/plu
 FILE: ../../../flutter/shell/platform/windows/client_wrapper/plugin_registrar_windows_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/dpi_utils.cc
 FILE: ../../../flutter/shell/platform/windows/dpi_utils.h
+FILE: ../../../flutter/shell/platform/windows/dpi_utils_unittests.cc
 FILE: ../../../flutter/shell/platform/windows/flutter_windows.cc
 FILE: ../../../flutter/shell/platform/windows/key_event_handler.cc
 FILE: ../../../flutter/shell/platform/windows/key_event_handler.h
diff --git a/shell/platform/windows/BUILD.gn b/shell/platform/windows/BUILD.gn
index 6b5eee870bc38..fee227ea7c9e0 100644
--- a/shell/platform/windows/BUILD.gn
+++ b/shell/platform/windows/BUILD.gn
@@ -109,6 +109,7 @@ executable("flutter_windows_unittests") {
   testonly = true
 
   sources = [
+    "dpi_utils_unittests.cc",
     "testing/win32_flutter_window_test.cc",
     "testing/win32_flutter_window_test.h",
     "testing/win32_window_test.cc",

From 6b06bb2c1ee35ef545665f1484e82b98852fbb9d Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 10 Feb 2020 14:36:34 -0800
Subject: [PATCH 35/38] Add test

---
 shell/platform/windows/dpi_utils_unittests.cc | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 shell/platform/windows/dpi_utils_unittests.cc

diff --git a/shell/platform/windows/dpi_utils_unittests.cc b/shell/platform/windows/dpi_utils_unittests.cc
new file mode 100644
index 0000000000000..335a4b5d765a3
--- /dev/null
+++ b/shell/platform/windows/dpi_utils_unittests.cc
@@ -0,0 +1,18 @@
+#include "flutter/shell/platform/windows/dpi_utils.h"
+#include "gtest/gtest.h"
+
+namespace flutter {
+namespace testing {
+
+TEST(DpiUtilsTest, NonZero) {
+  ASSERT_GT(GetDpiForHWND(nullptr),0);
+  ASSERT_GT(GetDpiForMonitor(nullptr),0);
+};
+
+TEST(DpiUtilsTest, EqualDpis) {
+  ASSERT_EQ(GetDpiForHWND(nullptr), GetDpiForMonitor(nullptr));
+  ASSERT_EQ(GetDpiForHWND(nullptr), 96);
+};
+
+}  // namespace testing
+}  // namespace flutter

From c379a981839fa10c6b07870adcb4a2362e7e7edc Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 10 Feb 2020 14:37:29 -0800
Subject: [PATCH 36/38] Remove test line

---
 shell/platform/windows/dpi_utils_unittests.cc | 1 -
 1 file changed, 1 deletion(-)

diff --git a/shell/platform/windows/dpi_utils_unittests.cc b/shell/platform/windows/dpi_utils_unittests.cc
index 335a4b5d765a3..ba1449da4adac 100644
--- a/shell/platform/windows/dpi_utils_unittests.cc
+++ b/shell/platform/windows/dpi_utils_unittests.cc
@@ -11,7 +11,6 @@ TEST(DpiUtilsTest, NonZero) {
 
 TEST(DpiUtilsTest, EqualDpis) {
   ASSERT_EQ(GetDpiForHWND(nullptr), GetDpiForMonitor(nullptr));
-  ASSERT_EQ(GetDpiForHWND(nullptr), 96);
 };
 
 }  // namespace testing

From d8bce83ef01d2c0b18f4def0f4d53d216029768d Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Mon, 10 Feb 2020 14:49:42 -0800
Subject: [PATCH 37/38] Format

---
 shell/platform/windows/dpi_utils_unittests.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/shell/platform/windows/dpi_utils_unittests.cc b/shell/platform/windows/dpi_utils_unittests.cc
index ba1449da4adac..66de44e96eb2a 100644
--- a/shell/platform/windows/dpi_utils_unittests.cc
+++ b/shell/platform/windows/dpi_utils_unittests.cc
@@ -5,8 +5,8 @@ namespace flutter {
 namespace testing {
 
 TEST(DpiUtilsTest, NonZero) {
-  ASSERT_GT(GetDpiForHWND(nullptr),0);
-  ASSERT_GT(GetDpiForMonitor(nullptr),0);
+  ASSERT_GT(GetDpiForHWND(nullptr), 0);
+  ASSERT_GT(GetDpiForMonitor(nullptr), 0);
 };
 
 TEST(DpiUtilsTest, EqualDpis) {

From 86ebe6ce400ac182871f8365a2577626a12a91e0 Mon Sep 17 00:00:00 2001
From: Francisco Madgaleno <franciscojma86@gmail.com>
Date: Tue, 11 Feb 2020 09:27:37 -0800
Subject: [PATCH 38/38] Clean tests

---
 shell/platform/windows/dpi_utils.cc                 | 13 +++++++------
 shell/platform/windows/dpi_utils_unittests.cc       |  8 ++++++--
 .../windows/testing/win32_flutter_window_test.h     |  8 ++++----
 shell/platform/windows/testing/win32_window_test.h  | 10 +++++-----
 4 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/shell/platform/windows/dpi_utils.cc b/shell/platform/windows/dpi_utils.cc
index 42b1ed0372ddc..20b706ef2fa95 100644
--- a/shell/platform/windows/dpi_utils.cc
+++ b/shell/platform/windows/dpi_utils.cc
@@ -85,11 +85,8 @@ UINT Win32DpiHelper::GetDpiForWindow(HWND hwnd) {
   }
 
   if (dpi_for_monitor_supported_) {
-    HMONITOR monitor;
-    if (hwnd == nullptr) {
-      const POINT target_point = {0, 0};
-      monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
-    } else {
+    HMONITOR monitor = nullptr;
+    if (hwnd != nullptr) {
       monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTOPRIMARY);
     }
     return GetDpiForMonitor(monitor);
@@ -102,6 +99,10 @@ UINT Win32DpiHelper::GetDpiForWindow(HWND hwnd) {
 
 UINT Win32DpiHelper::GetDpiForMonitor(HMONITOR monitor) {
   if (dpi_for_monitor_supported_) {
+    if (monitor == nullptr) {
+      const POINT target_point = {0, 0};
+      monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
+    }
     UINT dpi_x = 0, dpi_y = 0;
     HRESULT result =
         get_dpi_for_monitor_(monitor, kEffectiveDpiMonitorType, &dpi_x, &dpi_y);
@@ -110,7 +111,7 @@ UINT Win32DpiHelper::GetDpiForMonitor(HMONITOR monitor) {
     }
   }
   return kDefaultDpi;
-}
+}  // namespace
 
 Win32DpiHelper* GetHelper() {
   static Win32DpiHelper* dpi_helper = new Win32DpiHelper();
diff --git a/shell/platform/windows/dpi_utils_unittests.cc b/shell/platform/windows/dpi_utils_unittests.cc
index 66de44e96eb2a..d69da0588827b 100644
--- a/shell/platform/windows/dpi_utils_unittests.cc
+++ b/shell/platform/windows/dpi_utils_unittests.cc
@@ -1,3 +1,5 @@
+#include <windows.h>
+
 #include "flutter/shell/platform/windows/dpi_utils.h"
 #include "gtest/gtest.h"
 
@@ -9,8 +11,10 @@ TEST(DpiUtilsTest, NonZero) {
   ASSERT_GT(GetDpiForMonitor(nullptr), 0);
 };
 
-TEST(DpiUtilsTest, EqualDpis) {
-  ASSERT_EQ(GetDpiForHWND(nullptr), GetDpiForMonitor(nullptr));
+TEST(DpiUtilsTest, NullHwndUsesPrimaryMonitor) {
+  const POINT target_point = {0, 0};
+  HMONITOR monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTOPRIMARY);
+  ASSERT_EQ(GetDpiForHWND(nullptr), GetDpiForMonitor(monitor));
 };
 
 }  // namespace testing
diff --git a/shell/platform/windows/testing/win32_flutter_window_test.h b/shell/platform/windows/testing/win32_flutter_window_test.h
index 98ee519def32b..6da56d9383a5b 100644
--- a/shell/platform/windows/testing/win32_flutter_window_test.h
+++ b/shell/platform/windows/testing/win32_flutter_window_test.h
@@ -4,7 +4,6 @@
 
 #include <windowsx.h>
 
-#include "flutter/fml/macros.h"
 #include "flutter/shell/platform/windows/win32_flutter_window.h"
 
 namespace flutter {
@@ -14,9 +13,12 @@ namespace testing {
 class Win32FlutterWindowTest : public Win32FlutterWindow {
  public:
   Win32FlutterWindowTest(int width, int height);
-
   virtual ~Win32FlutterWindowTest();
 
+  // Prevent copying.
+  Win32FlutterWindowTest(Win32FlutterWindowTest const&) = delete;
+  Win32FlutterWindowTest& operator=(Win32FlutterWindowTest const&) = delete;
+
   // |Win32Window|
   void OnFontChange() override;
 
@@ -24,8 +26,6 @@ class Win32FlutterWindowTest : public Win32FlutterWindow {
 
  private:
   bool on_font_change_called_ = false;
-
-  FML_DISALLOW_COPY_AND_ASSIGN(Win32FlutterWindowTest);
 };
 
 }  // namespace testing
diff --git a/shell/platform/windows/testing/win32_window_test.h b/shell/platform/windows/testing/win32_window_test.h
index 4bb310e036b2a..ccefdfe717dbf 100644
--- a/shell/platform/windows/testing/win32_window_test.h
+++ b/shell/platform/windows/testing/win32_window_test.h
@@ -4,7 +4,6 @@
 
 #include <windowsx.h>
 
-#include "flutter/fml/macros.h"
 #include "flutter/shell/platform/windows/win32_window.h"
 
 namespace flutter {
@@ -15,7 +14,11 @@ namespace testing {
 class Win32WindowTest : public Win32Window {
  public:
   Win32WindowTest();
-  ~Win32WindowTest();
+  virtual ~Win32WindowTest();
+
+  // Prevent copying.
+  Win32WindowTest(Win32WindowTest const&) = delete;
+  Win32WindowTest& operator=(Win32WindowTest const&) = delete;
 
   // Wrapper for GetCurrentDPI() which is a protected method.
   UINT GetDpi();
@@ -49,9 +52,6 @@ class Win32WindowTest : public Win32Window {
 
   // |Win32Window|
   void OnFontChange() override;
-
- private:
-  FML_DISALLOW_COPY_AND_ASSIGN(Win32WindowTest);
 };
 
 }  // namespace testing