From 35af6f8fc3fdbf68205d43bf190b1dc584b86bc6 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Mon, 22 Jun 2020 09:25:37 -0700
Subject: [PATCH 01/13] Revert "Revert "Add `GetBoundingRectAfterMutations` to
 EmbeddedViewParams to calculate the final bounding rect for platform view
 (#19170)" (#19204)"

This reverts commit 9cecc5f115ebfd06251d6eebdbb532e462a01e07.
---
 ci/licenses_golden/licenses_flutter           |  1 +
 flow/BUILD.gn                                 |  1 +
 flow/embedded_view_params_unittests.cc        | 98 +++++++++++++++++++
 flow/embedded_views.h                         | 46 +++++++--
 flow/layers/platform_view_layer.cc            |  7 +-
 .../framework/Source/FlutterPlatformViews.mm  |  7 +-
 shell/platform/embedder/embedder_layers.cc    | 10 +-
 7 files changed, 148 insertions(+), 22 deletions(-)
 create mode 100644 flow/embedded_view_params_unittests.cc

diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
index 242783e947b27..4cd541e0fed4f 100755
--- a/ci/licenses_golden/licenses_flutter
+++ b/ci/licenses_golden/licenses_flutter
@@ -26,6 +26,7 @@ FILE: ../../../flutter/common/task_runners.cc
 FILE: ../../../flutter/common/task_runners.h
 FILE: ../../../flutter/flow/compositor_context.cc
 FILE: ../../../flutter/flow/compositor_context.h
+FILE: ../../../flutter/flow/embedded_view_params_unittests.cc
 FILE: ../../../flutter/flow/embedded_views.cc
 FILE: ../../../flutter/flow/embedded_views.h
 FILE: ../../../flutter/flow/gl_context_switch.cc
diff --git a/flow/BUILD.gn b/flow/BUILD.gn
index a8c3592ccecbf..85c55d2cfba0b 100644
--- a/flow/BUILD.gn
+++ b/flow/BUILD.gn
@@ -130,6 +130,7 @@ executable("flow_unittests") {
   testonly = true
 
   sources = [
+    "embedded_view_params_unittests.cc",
     "flow_run_all_unittests.cc",
     "flow_test_utils.cc",
     "flow_test_utils.h",
diff --git a/flow/embedded_view_params_unittests.cc b/flow/embedded_view_params_unittests.cc
new file mode 100644
index 0000000000000..cb94936e17ddf
--- /dev/null
+++ b/flow/embedded_view_params_unittests.cc
@@ -0,0 +1,98 @@
+// 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 "flutter/flow/embedded_views.h"
+#include "flutter/fml/logging.h"
+#include "gtest/gtest.h"
+
+namespace flutter {
+namespace testing {
+
+TEST(EmbeddedViewParams, GetBoundingRectAfterMutationsWithNoMutations) {
+  MutatorsStack stack;
+  SkMatrix matrix;
+
+  EmbeddedViewParams params(matrix, SkSize::Make(1, 1), stack);
+  const SkRect& rect = params.finalBoundingRect();
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.x(), 0));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.y(), 0));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.width(), 1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.height(), 1));
+}
+
+TEST(EmbeddedViewParams, GetBoundingRectAfterMutationsWithScale) {
+  MutatorsStack stack;
+  SkMatrix matrix = SkMatrix::Scale(2, 2);
+  stack.PushTransform(matrix);
+
+  EmbeddedViewParams params(matrix, SkSize::Make(1, 1), stack);
+  const SkRect& rect = params.finalBoundingRect();
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.x(), 0));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.y(), 0));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.width(), 2));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.height(), 2));
+}
+
+TEST(EmbeddedViewParams, GetBoundingRectAfterMutationsWithTranslate) {
+  MutatorsStack stack;
+  SkMatrix matrix = SkMatrix::MakeTrans(1, 1);
+  stack.PushTransform(matrix);
+
+  EmbeddedViewParams params(matrix, SkSize::Make(1, 1), stack);
+  const SkRect& rect = params.finalBoundingRect();
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.x(), 1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.y(), 1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.width(), 1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.height(), 1));
+}
+
+TEST(EmbeddedViewParams, GetBoundingRectAfterMutationsWithRotation90) {
+  MutatorsStack stack;
+  SkMatrix matrix;
+  matrix.setRotate(90);
+  stack.PushTransform(matrix);
+
+  EmbeddedViewParams params(matrix, SkSize::Make(1, 1), stack);
+  const SkRect& rect = params.finalBoundingRect();
+
+  FML_DLOG(ERROR) << rect.x();
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.x(), -1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.y(), 0));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.width(), 1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.height(), 1));
+}
+
+TEST(EmbeddedViewParams, GetBoundingRectAfterMutationsWithRotation45) {
+  MutatorsStack stack;
+  SkMatrix matrix;
+  matrix.setRotate(45);
+  stack.PushTransform(matrix);
+
+  EmbeddedViewParams params(matrix, SkSize::Make(1, 1), stack);
+  const SkRect& rect = params.finalBoundingRect();
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.x(), -sqrt(2) / 2));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.y(), 0));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.width(), sqrt(2)));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.height(), sqrt(2)));
+}
+
+TEST(EmbeddedViewParams,
+     GetBoundingRectAfterMutationsWithTranslateScaleAndRotation) {
+  SkMatrix matrix = SkMatrix::MakeTrans(2, 2);
+  matrix.preScale(3, 3);
+  matrix.preRotate(90);
+
+  MutatorsStack stack;
+  stack.PushTransform(matrix);
+
+  EmbeddedViewParams params(matrix, SkSize::Make(1, 1), stack);
+  const SkRect& rect = params.finalBoundingRect();
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.x(), -1));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.y(), 2));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.width(), 3));
+  ASSERT_TRUE(SkScalarNearlyEqual(rect.height(), 3));
+}
+
+}  // namespace testing
+}  // namespace flutter
diff --git a/flow/embedded_views.h b/flow/embedded_views.h
index 9cc90860101a8..3493f02be7415 100644
--- a/flow/embedded_views.h
+++ b/flow/embedded_views.h
@@ -186,21 +186,49 @@ class EmbeddedViewParams {
  public:
   EmbeddedViewParams() = default;
 
+  EmbeddedViewParams(SkMatrix matrix,
+                     SkSize size_points,
+                     MutatorsStack mutators_stack)
+      : matrix_(matrix),
+        size_points_(size_points),
+        mutators_stack_(mutators_stack) {
+    SkPath path;
+    SkRect starting_rect = SkRect::MakeSize(size_points);
+    path.addRect(starting_rect);
+    path.transform(matrix);
+    final_bounding_rect_ = path.computeTightBounds();
+  }
+
   EmbeddedViewParams(const EmbeddedViewParams& other) {
-    offsetPixels = other.offsetPixels;
-    sizePoints = other.sizePoints;
-    mutatorsStack = other.mutatorsStack;
+    size_points_ = other.size_points_;
+    mutators_stack_ = other.mutators_stack_;
+    matrix_ = other.matrix_;
+    final_bounding_rect_ = other.final_bounding_rect_;
   };
 
-  SkPoint offsetPixels;
-  SkSize sizePoints;
-  MutatorsStack mutatorsStack;
+  // The original size of the platform view before any mutation matrix is
+  // applied.
+  const SkSize& sizePoints() const { return size_points_; };
+  // The mutators stack contains the detailed step by step mutations for this
+  // platform view.
+  const MutatorsStack& mutatorsStack() const { return mutators_stack_; };
+  // The bounding rect of the platform view after applying all the mutations.
+  //
+  // Clippings are ignored.
+  const SkRect& finalBoundingRect() const { return final_bounding_rect_; }
 
   bool operator==(const EmbeddedViewParams& other) const {
-    return offsetPixels == other.offsetPixels &&
-           sizePoints == other.sizePoints &&
-           mutatorsStack == other.mutatorsStack;
+    return size_points_ == other.size_points_ &&
+           mutators_stack_ == other.mutators_stack_ &&
+           final_bounding_rect_ == other.final_bounding_rect_ &&
+           matrix_ == other.matrix_;
   }
+
+ private:
+  SkMatrix matrix_;
+  SkSize size_points_;
+  MutatorsStack mutators_stack_;
+  SkRect final_bounding_rect_;
 };
 
 enum class PostPrerollResult { kResubmitFrame, kSuccess };
diff --git a/flow/layers/platform_view_layer.cc b/flow/layers/platform_view_layer.cc
index 81c40a99f0d89..551a270b16542 100644
--- a/flow/layers/platform_view_layer.cc
+++ b/flow/layers/platform_view_layer.cc
@@ -27,11 +27,8 @@ void PlatformViewLayer::Preroll(PrerollContext* context,
   }
   context->has_platform_view = true;
   std::unique_ptr<EmbeddedViewParams> params =
-      std::make_unique<EmbeddedViewParams>();
-  params->offsetPixels =
-      SkPoint::Make(matrix.getTranslateX(), matrix.getTranslateY());
-  params->sizePoints = size_;
-  params->mutatorsStack = context->mutators_stack;
+      std::make_unique<EmbeddedViewParams>(matrix, size_,
+                                           context->mutators_stack);
   context->view_embedder->PrerollCompositeEmbeddedView(view_id_,
                                                        std::move(params));
 }
diff --git a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
index f590701e7e2cb..474e9f084c1ee 100644
--- a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
+++ b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
@@ -407,13 +407,14 @@
 
 void FlutterPlatformViewsController::CompositeWithParams(int view_id,
                                                          const EmbeddedViewParams& params) {
-  CGRect frame = CGRectMake(0, 0, params.sizePoints.width(), params.sizePoints.height());
+  CGRect frame = CGRectMake(0, 0, params.sizePoints().width(), params.sizePoints().height());
   UIView* touchInterceptor = touch_interceptors_[view_id].get();
   touchInterceptor.layer.transform = CATransform3DIdentity;
   touchInterceptor.frame = frame;
   touchInterceptor.alpha = 1;
 
-  int currentClippingCount = CountClips(params.mutatorsStack);
+  const MutatorsStack& mutatorStack = params.mutatorsStack();
+  int currentClippingCount = CountClips(mutatorStack);
   int previousClippingCount = clip_count_[view_id];
   if (currentClippingCount != previousClippingCount) {
     clip_count_[view_id] = currentClippingCount;
@@ -424,7 +425,7 @@
         ReconstructClipViewsChain(currentClippingCount, touchInterceptor, oldPlatformViewRoot);
     root_views_[view_id] = fml::scoped_nsobject<UIView>([newPlatformViewRoot retain]);
   }
-  ApplyMutators(params.mutatorsStack, touchInterceptor);
+  ApplyMutators(mutatorStack, touchInterceptor);
 }
 
 SkCanvas* FlutterPlatformViewsController::CompositeEmbeddedView(int view_id) {
diff --git a/shell/platform/embedder/embedder_layers.cc b/shell/platform/embedder/embedder_layers.cc
index 3b634235f820a..4716ea15683dd 100644
--- a/shell/platform/embedder/embedder_layers.cc
+++ b/shell/platform/embedder/embedder_layers.cc
@@ -108,7 +108,7 @@ void EmbedderLayers::PushPlatformViewLayer(
     view.struct_size = sizeof(FlutterPlatformView);
     view.identifier = identifier;
 
-    const auto& mutators = params.mutatorsStack;
+    const auto& mutators = params.mutatorsStack();
 
     std::vector<const FlutterPlatformViewMutation*> mutations_array;
 
@@ -180,10 +180,10 @@ void EmbedderLayers::PushPlatformViewLayer(
   layer.platform_view = platform_views_referenced_.back().get();
 
   const auto layer_bounds =
-      SkRect::MakeXYWH(params.offsetPixels.x(),                          //
-                       params.offsetPixels.y(),                          //
-                       params.sizePoints.width() * device_pixel_ratio_,  //
-                       params.sizePoints.height() * device_pixel_ratio_  //
+      SkRect::MakeXYWH(params.finalBoundingRect().x(),                     //
+                       params.finalBoundingRect().y(),                     //
+                       params.sizePoints().width() * device_pixel_ratio_,  //
+                       params.sizePoints().height() * device_pixel_ratio_  //
       );
 
   const auto transformed_layer_bounds =

From fb89d64808234c2e364d7ea83c3b5aba02036f01 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Mon, 22 Jun 2020 09:28:15 -0700
Subject: [PATCH 02/13] fix compile error

---
 .../external_view_embedder/external_view_embedder.cc      | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.cc b/shell/platform/android/external_view_embedder/external_view_embedder.cc
index 9485eedff5491..9d5dae31c89f1 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder.cc
+++ b/shell/platform/android/external_view_embedder/external_view_embedder.cc
@@ -63,10 +63,10 @@ SkRect AndroidExternalViewEmbedder::GetViewRect(int view_id) const {
   const EmbeddedViewParams& params = view_params_.at(view_id);
   // TODO(egarciad): The rect should be computed from the mutator stack.
   // https://github.com/flutter/flutter/issues/59821
-  return SkRect::MakeXYWH(params.offsetPixels.x(),                          //
-                          params.offsetPixels.y(),                          //
-                          params.sizePoints.width() * device_pixel_ratio_,  //
-                          params.sizePoints.height() * device_pixel_ratio_  //
+  return SkRect::MakeXYWH(params.finalBoundingRect().x(),                          //
+                          params.finalBoundingRect().y(),                          //
+                          params.sizePoints().width() * device_pixel_ratio_,  //
+                          params.sizePoints().height() * device_pixel_ratio_  //
   );
 }
 

From 825ca5a08c5f2633919e122c461511344e30530b Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Mon, 22 Jun 2020 12:13:29 -0700
Subject: [PATCH 03/13] fix external_view_embedder_unittests

---
 .../external_view_embedder.cc                 |  4 +-
 .../external_view_embedder_unittests.cc       | 45 ++++++++++++-------
 2 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.cc b/shell/platform/android/external_view_embedder/external_view_embedder.cc
index 9d5dae31c89f1..f1f46ab21b49c 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder.cc
+++ b/shell/platform/android/external_view_embedder/external_view_embedder.cc
@@ -63,8 +63,8 @@ SkRect AndroidExternalViewEmbedder::GetViewRect(int view_id) const {
   const EmbeddedViewParams& params = view_params_.at(view_id);
   // TODO(egarciad): The rect should be computed from the mutator stack.
   // https://github.com/flutter/flutter/issues/59821
-  return SkRect::MakeXYWH(params.finalBoundingRect().x(),                          //
-                          params.finalBoundingRect().y(),                          //
+  return SkRect::MakeXYWH(params.finalBoundingRect().x(),                     //
+                          params.finalBoundingRect().y(),                     //
                           params.sizePoints().width() * device_pixel_ratio_,  //
                           params.sizePoints().height() * device_pixel_ratio_  //
   );
diff --git a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
index bba1c126564a1..a0551a0a39dea 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
+++ b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
@@ -198,9 +198,11 @@ TEST(AndroidExternalViewEmbedder, PlatformViewRect) {
   embedder->BeginFrame(SkISize::Make(100, 100), nullptr, 1.5,
                        raster_thread_merger);
 
-  auto view_params = std::make_unique<EmbeddedViewParams>();
-  view_params->offsetPixels = SkPoint::Make(10, 20);
-  view_params->sizePoints = SkSize::Make(30, 40);
+  MutatorsStack stack;
+  SkMatrix matrix = SkMatrix::MakeTrans(10, 20);
+  stack.PushTransform(matrix);
+  auto view_params =
+      std::make_unique<EmbeddedViewParams>(matrix, SkSize::Make(30, 40), stack);
 
   auto view_id = 0;
   embedder->PrerollCompositeEmbeddedView(view_id, std::move(view_params));
@@ -219,14 +221,21 @@ TEST(AndroidExternalViewEmbedder, PlatformViewRect__ChangedParams) {
                        raster_thread_merger);
 
   auto view_id = 0;
-  auto view_params_1 = std::make_unique<EmbeddedViewParams>();
-  view_params_1->offsetPixels = SkPoint::Make(10, 20);
-  view_params_1->sizePoints = SkSize::Make(30, 40);
+
+  MutatorsStack stack1;
+  SkMatrix matrix1 = SkMatrix::MakeTrans(10, 20);
+  stack1.PushTransform(matrix1);
+  auto view_params_1 = std::make_unique<EmbeddedViewParams>(
+      matrix1, SkSize::Make(30, 40), stack1);
+
   embedder->PrerollCompositeEmbeddedView(view_id, std::move(view_params_1));
 
-  auto view_params_2 = std::make_unique<EmbeddedViewParams>();
-  view_params_2->offsetPixels = SkPoint::Make(50, 60);
-  view_params_2->sizePoints = SkSize::Make(70, 80);
+  MutatorsStack stack2;
+  SkMatrix matrix2 = SkMatrix::MakeTrans(50, 60);
+  stack2.PushTransform(matrix2);
+  auto view_params_2 = std::make_unique<EmbeddedViewParams>(
+      matrix2, SkSize::Make(70, 80), stack2);
+
   embedder->PrerollCompositeEmbeddedView(view_id, std::move(view_params_2));
 
   ASSERT_EQ(SkRect::MakeXYWH(50, 60, 105, 120), embedder->GetViewRect(view_id));
@@ -281,11 +290,14 @@ TEST(AndroidExternalViewEmbedder, SubmitFrame__RecycleSurfaces) {
     embedder->BeginFrame(frame_size, nullptr, 1.5, raster_thread_merger);
 
     // Add an Android view.
-    auto view_params_1 = std::make_unique<EmbeddedViewParams>();
-    view_params_1->offsetPixels = SkPoint::Make(100, 100);
+    MutatorsStack stack1;
+    SkMatrix matrix1 = SkMatrix::MakeTrans(100, 100);
+    stack1.PushTransform(matrix1);
     // TODO(egarciad): Investigate why Flow applies the device pixel ratio to
     // the offsetPixels, but not the sizePoints.
-    view_params_1->sizePoints = SkSize::Make(200, 200);
+    auto view_params_1 = std::make_unique<EmbeddedViewParams>(
+        matrix1, SkSize::Make(200, 200), stack1);
+
     embedder->PrerollCompositeEmbeddedView(0, std::move(view_params_1));
     // This is the recording canvas flow writes to.
     auto canvas_1 = embedder->CompositeEmbeddedView(0);
@@ -329,11 +341,14 @@ TEST(AndroidExternalViewEmbedder, SubmitFrame__RecycleSurfaces) {
     embedder->BeginFrame(frame_size, nullptr, 1.5, raster_thread_merger);
 
     // Add an Android view.
-    auto view_params_1 = std::make_unique<EmbeddedViewParams>();
-    view_params_1->offsetPixels = SkPoint::Make(100, 100);
+    MutatorsStack stack1;
+    SkMatrix matrix1 = SkMatrix::MakeTrans(100, 100);
+    stack1.PushTransform(matrix1);
     // TODO(egarciad): Investigate why Flow applies the device pixel ratio to
     // the offsetPixels, but not the sizePoints.
-    view_params_1->sizePoints = SkSize::Make(200, 200);
+    auto view_params_1 = std::make_unique<EmbeddedViewParams>(
+        matrix1, SkSize::Make(200, 200), stack1);
+
     embedder->PrerollCompositeEmbeddedView(0, std::move(view_params_1));
     // This is the recording canvas flow writes to.
     auto canvas_1 = embedder->CompositeEmbeddedView(0);

From 86967e6704a3310521b3b3eb0397719fe583b28a Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 10:41:00 -0700
Subject: [PATCH 04/13] draft

---
 common/settings.h                             |  2 +
 .../platform/android/android_shell_holder.cc  | 45 ++++++++++++++-----
 shell/platform/android/flutter_main.cc        |  8 ++--
 shell/platform/android/flutter_main.h         |  3 +-
 .../engine/loader/FlutterLoader.java          |  8 +++-
 5 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/common/settings.h b/common/settings.h
index 52abe1994bd60..f963cd298ae5f 100644
--- a/common/settings.h
+++ b/common/settings.h
@@ -213,6 +213,8 @@ struct Settings {
   /// to log a timeline event that tracks the latency of engine startup.
   std::chrono::microseconds engine_start_timestamp = {};
 
+  bool use_embedded_view = false;
+
   std::string ToString() const;
 };
 
diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index 62f8acf6fc8fd..a0ea1d0457410 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -101,20 +101,45 @@ AndroidShellHolder::AndroidShellHolder(
     ui_runner = thread_host_.ui_thread->GetTaskRunner();
     io_runner = thread_host_.io_thread->GetTaskRunner();
   }
-  flutter::TaskRunners task_runners(thread_label,     // label
-                                    platform_runner,  // platform
-                                    gpu_runner,       // raster
-                                    ui_runner,        // ui
-                                    io_runner         // io
-  );
-
-  shell_ =
+  if (settings.use_embedded_view) {
+    // Embedded views requires the gpu and the platform views to be the same.
+    // The plan is to eventually dynamically merge the threads when there's a
+    // platform view in the layer tree.
+    // For now we use a fixed thread configuration with the same thread used as the
+    // gpu and platform task runner.
+    // TODO(amirh/chinmaygarde): remove this, and dynamically change the thread configuration.
+    // https://github.com/flutter/flutter/issues/23975
+    // https://github.com/flutter/flutter/issues/59930
+    flutter::TaskRunners task_runners(thread_label,     // label
+                                      platform_runner,  // platform
+                                      platform_runner,       // raster
+                                      ui_runner,        // ui
+                                      io_runner         // io
+    );
+
+    shell_ =
       Shell::Create(task_runners,             // task runners
                     GetDefaultWindowData(),   // window data
                     settings_,                // settings
                     on_create_platform_view,  // platform view create callback
                     on_create_rasterizer      // rasterizer create callback
       );
+  } else {
+    flutter::TaskRunners task_runners(thread_label,     // label
+                                      platform_runner,  // platform
+                                      gpu_runner,       // raster
+                                      ui_runner,        // ui
+                                      io_runner         // io
+    );
+
+    shell_ =
+      Shell::Create(task_runners,             // task runners
+                    GetDefaultWindowData(),   // window data
+                    settings_,                // settings
+                    on_create_platform_view,  // platform view create callback
+                    on_create_rasterizer      // rasterizer create callback
+      );
+  }
 
   platform_view_ = weak_platform_view;
   FML_DCHECK(platform_view_);
@@ -122,7 +147,7 @@ AndroidShellHolder::AndroidShellHolder(
   is_valid_ = shell_ != nullptr;
 
   if (is_valid_) {
-    task_runners.GetRasterTaskRunner()->PostTask([]() {
+    shell_->GetTaskRunners().GetRasterTaskRunner()->PostTask([]() {
       // Android describes -8 as "most important display threads, for
       // compositing the screen and retrieving input events". Conservatively
       // set the raster thread to slightly lower priority than it.
@@ -134,7 +159,7 @@ AndroidShellHolder::AndroidShellHolder(
         }
       }
     });
-    task_runners.GetUITaskRunner()->PostTask([]() {
+    shell_->GetTaskRunners().GetUITaskRunner()->PostTask([]() {
       if (::setpriority(PRIO_PROCESS, gettid(), -1) != 0) {
         FML_LOG(ERROR) << "Failed to set UI task runner priority";
       }
diff --git a/shell/platform/android/flutter_main.cc b/shell/platform/android/flutter_main.cc
index 1493bf4f0d161..24538e95274f2 100644
--- a/shell/platform/android/flutter_main.cc
+++ b/shell/platform/android/flutter_main.cc
@@ -63,7 +63,8 @@ void FlutterMain::Init(JNIEnv* env,
                        jstring kernelPath,
                        jstring appStoragePath,
                        jstring engineCachesPath,
-                       jlong initTimeMillis) {
+                       jlong initTimeMillis,
+                       jboolean useEmbeddedView) {
   std::vector<std::string> args;
   args.push_back("flutter");
   for (auto& arg : fml::jni::StringArrayToVector(env, jargs)) {
@@ -99,6 +100,8 @@ void FlutterMain::Init(JNIEnv* env,
     }
   }
 
+  settings.use_embedded_view = useEmbeddedView;
+
   settings.task_observer_add = [](intptr_t key, fml::closure callback) {
     fml::MessageLoop::GetCurrent().AddTaskObserver(key, std::move(callback));
   };
@@ -165,8 +168,7 @@ bool FlutterMain::Register(JNIEnv* env) {
   static const JNINativeMethod methods[] = {
       {
           .name = "nativeInit",
-          .signature = "(Landroid/content/Context;[Ljava/lang/String;Ljava/"
-                       "lang/String;Ljava/lang/String;Ljava/lang/String;J)V",
+          .signature = "(Landroid/content/Context;[Ljava/lang/String;Ljava/",
           .fnPtr = reinterpret_cast<void*>(&Init),
       },
       {
diff --git a/shell/platform/android/flutter_main.h b/shell/platform/android/flutter_main.h
index 171800b3ec500..6a32a88bae909 100644
--- a/shell/platform/android/flutter_main.h
+++ b/shell/platform/android/flutter_main.h
@@ -36,7 +36,8 @@ class FlutterMain {
                    jstring kernelPath,
                    jstring appStoragePath,
                    jstring engineCachesPath,
-                   jlong initTimeMillis);
+                   jlong initTimeMillis,
+                   jboolean useEmbeddedView);
 
   void SetupObservatoryUriCallback(JNIEnv* env);
 
diff --git a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
index c57d8c86b8374..0c830f77991a9 100644
--- a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
+++ b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
@@ -201,7 +201,6 @@ public void ensureInitializationComplete(
               + applicationInfo.nativeLibraryDir
               + File.separator
               + DEFAULT_LIBRARY);
-
       if (args != null) {
         Collections.addAll(shellArgs, args);
       }
@@ -234,13 +233,18 @@ public void ensureInitializationComplete(
       }
 
       long initTimeMillis = SystemClock.uptimeMillis() - initStartTimestampMillis;
+
+      Bundle bundle = applicationInfo.metaData;
+      boolean use_embedded_view = bundle.getBoolean("io.flutter.embedded_views_preview");
+
       FlutterJNI.nativeInit(
           applicationContext,
           shellArgs.toArray(new String[0]),
           kernelPath,
           result.appStoragePath,
           result.engineCachesPath,
-          initTimeMillis);
+          initTimeMillis,
+          use_embedded_view);
 
       initialized = true;
     } catch (Exception e) {

From 63f4e4166128296b2b2e38afe50ec5fb75ada8ea Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 10:42:07 -0700
Subject: [PATCH 05/13] add extra bool to nativeInit

---
 shell/platform/android/flutter_main.cc | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/shell/platform/android/flutter_main.cc b/shell/platform/android/flutter_main.cc
index 24538e95274f2..1493bf4f0d161 100644
--- a/shell/platform/android/flutter_main.cc
+++ b/shell/platform/android/flutter_main.cc
@@ -63,8 +63,7 @@ void FlutterMain::Init(JNIEnv* env,
                        jstring kernelPath,
                        jstring appStoragePath,
                        jstring engineCachesPath,
-                       jlong initTimeMillis,
-                       jboolean useEmbeddedView) {
+                       jlong initTimeMillis) {
   std::vector<std::string> args;
   args.push_back("flutter");
   for (auto& arg : fml::jni::StringArrayToVector(env, jargs)) {
@@ -100,8 +99,6 @@ void FlutterMain::Init(JNIEnv* env,
     }
   }
 
-  settings.use_embedded_view = useEmbeddedView;
-
   settings.task_observer_add = [](intptr_t key, fml::closure callback) {
     fml::MessageLoop::GetCurrent().AddTaskObserver(key, std::move(callback));
   };
@@ -168,7 +165,8 @@ bool FlutterMain::Register(JNIEnv* env) {
   static const JNINativeMethod methods[] = {
       {
           .name = "nativeInit",
-          .signature = "(Landroid/content/Context;[Ljava/lang/String;Ljava/",
+          .signature = "(Landroid/content/Context;[Ljava/lang/String;Ljava/"
+                       "lang/String;Ljava/lang/String;Ljava/lang/String;J)V",
           .fnPtr = reinterpret_cast<void*>(&Init),
       },
       {

From d3a554f81f013e3d95d72df2ee2725990c2e0e64 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 12:13:23 -0700
Subject: [PATCH 06/13] fix nativeInit params

---
 common/settings.h                                        | 5 +++++
 shell/platform/android/android_shell_holder.cc           | 2 ++
 shell/platform/android/flutter_main.cc                   | 9 +++++++--
 shell/platform/android/flutter_main.h                    | 2 ++
 .../android/io/flutter/embedding/engine/FlutterJNI.java  | 3 ++-
 .../flutter/embedding/engine/loader/FlutterLoader.java   | 2 ++
 6 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/common/settings.h b/common/settings.h
index f963cd298ae5f..ea4970747fbe9 100644
--- a/common/settings.h
+++ b/common/settings.h
@@ -213,6 +213,11 @@ struct Settings {
   /// to log a timeline event that tracks the latency of engine startup.
   std::chrono::microseconds engine_start_timestamp = {};
 
+  /// Does the application claim that it uses the android embedded view for platform views.
+  ///
+  /// A `true` value will result the raster task runner always run on the platform thread.
+  // TODO(cyanlaz): Remove this when dynamic thread merging is done.
+  // https://github.com/flutter/flutter/issues/59930
   bool use_embedded_view = false;
 
   std::string ToString() const;
diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index a0ea1d0457410..6109d1d05a5fe 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -102,6 +102,7 @@ AndroidShellHolder::AndroidShellHolder(
     io_runner = thread_host_.io_thread->GetTaskRunner();
   }
   if (settings.use_embedded_view) {
+    FML_DLOG(ERROR) << "use_embedded_view TRUE";
     // Embedded views requires the gpu and the platform views to be the same.
     // The plan is to eventually dynamically merge the threads when there's a
     // platform view in the layer tree.
@@ -125,6 +126,7 @@ AndroidShellHolder::AndroidShellHolder(
                     on_create_rasterizer      // rasterizer create callback
       );
   } else {
+    FML_DLOG(ERROR) << "use_embedded_view FALSE";
     flutter::TaskRunners task_runners(thread_label,     // label
                                       platform_runner,  // platform
                                       gpu_runner,       // raster
diff --git a/shell/platform/android/flutter_main.cc b/shell/platform/android/flutter_main.cc
index 1493bf4f0d161..70fcde2868084 100644
--- a/shell/platform/android/flutter_main.cc
+++ b/shell/platform/android/flutter_main.cc
@@ -63,7 +63,8 @@ void FlutterMain::Init(JNIEnv* env,
                        jstring kernelPath,
                        jstring appStoragePath,
                        jstring engineCachesPath,
-                       jlong initTimeMillis) {
+                       jlong initTimeMillis,
+                       jboolean useEmbeddedView) {
   std::vector<std::string> args;
   args.push_back("flutter");
   for (auto& arg : fml::jni::StringArrayToVector(env, jargs)) {
@@ -73,6 +74,10 @@ void FlutterMain::Init(JNIEnv* env,
 
   auto settings = SettingsFromCommandLine(command_line);
 
+  // TODO(cyanlaz): Remove this when dynamic thread merging is done.
+  // https://github.com/flutter/flutter/issues/59930
+  settings.use_embedded_view = useEmbeddedView;
+
   int64_t init_time_micros = initTimeMillis * 1000;
   settings.engine_start_timestamp =
       std::chrono::microseconds(Dart_TimelineGetMicros() - init_time_micros);
@@ -166,7 +171,7 @@ bool FlutterMain::Register(JNIEnv* env) {
       {
           .name = "nativeInit",
           .signature = "(Landroid/content/Context;[Ljava/lang/String;Ljava/"
-                       "lang/String;Ljava/lang/String;Ljava/lang/String;J)V",
+                       "lang/String;Ljava/lang/String;Ljava/lang/String;J;Z)V",
           .fnPtr = reinterpret_cast<void*>(&Init),
       },
       {
diff --git a/shell/platform/android/flutter_main.h b/shell/platform/android/flutter_main.h
index 6a32a88bae909..097dd9f5bee26 100644
--- a/shell/platform/android/flutter_main.h
+++ b/shell/platform/android/flutter_main.h
@@ -29,6 +29,8 @@ class FlutterMain {
 
   FlutterMain(flutter::Settings settings);
 
+  // TODO(cyanlaz): Remove `useEmbeddedView` when dynamic thread merging is done.
+  // https://github.com/flutter/flutter/issues/59930
   static void Init(JNIEnv* env,
                    jclass clazz,
                    jobject context,
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
index 5fb4e337c6ef5..5e43047bf4789 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
@@ -110,7 +110,8 @@ public static native void nativeInit(
       @Nullable String bundlePath,
       @NonNull String appStoragePath,
       @NonNull String engineCachesPath,
-      long initTimeMillis);
+      long initTimeMillis,
+      boolean useEmbeddedView);
 
   /**
    * Prefetch the default font manager provided by SkFontMgr::RefDefault() which is a process-wide
diff --git a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
index 0c830f77991a9..50f4c9ffbda8e 100644
--- a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
+++ b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
@@ -234,6 +234,8 @@ public void ensureInitializationComplete(
 
       long initTimeMillis = SystemClock.uptimeMillis() - initStartTimestampMillis;
 
+      // TODO(cyanlaz): Remove this when dynamic thread merging is done.
+      // https://github.com/flutter/flutter/issues/59930
       Bundle bundle = applicationInfo.metaData;
       boolean use_embedded_view = bundle.getBoolean("io.flutter.embedded_views_preview");
 

From 227e151dc59e16ce4ebbba723fac31db346c1b47 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 13:45:40 -0700
Subject: [PATCH 07/13] parse use_embedded_view flag

---
 shell/common/switches.cc                               |  2 ++
 shell/common/switches.h                                |  7 +++++++
 shell/platform/android/android_shell_holder.cc         | 10 +++++-----
 shell/platform/android/flutter_main.cc                 |  9 ++-------
 shell/platform/android/flutter_main.h                  |  5 +----
 .../io/flutter/embedding/engine/FlutterJNI.java        |  3 +--
 .../flutter/embedding/engine/loader/FlutterLoader.java |  6 ++++--
 shell/platform/android/platform_view_android.cc        |  8 +++++---
 shell/platform/android/platform_view_android.h         |  6 ++++--
 9 files changed, 31 insertions(+), 25 deletions(-)

diff --git a/shell/common/switches.cc b/shell/common/switches.cc
index e3f6e985d4d74..235a5148410d3 100644
--- a/shell/common/switches.cc
+++ b/shell/common/switches.cc
@@ -227,6 +227,8 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
                                                             : "127.0.0.1";
   }
 
+  settings.use_embedded_view = command_line.HasOption(FlagForSwitch(Switch::UseEmbeddedView));
+
   // Set Observatory Port
   if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryPort))) {
     if (!GetSwitchValue(command_line, Switch::DeviceObservatoryPort,
diff --git a/shell/common/switches.h b/shell/common/switches.h
index 3bef7d645dde9..62d0683ae866d 100644
--- a/shell/common/switches.h
+++ b/shell/common/switches.h
@@ -189,6 +189,13 @@ DEF_SWITCH(
     "Uses separate threads for the platform, UI, GPU and IO task runners. "
     "By default, a single thread is used for all task runners. Only available "
     "in the flutter_tester.")
+// TODO(cyanlaz): Remove this when dynamic thread merging is done.
+// https://github.com/flutter/flutter/issues/59930
+DEF_SWITCH(UseEmbeddedView,
+           "use-embedded-view",
+           "Whether an android application uses embedded views."
+           "This is a temporary flag to make the raster task runner runs on the platform thread."
+           "This flag should be removed once the dynamic thread merging is enabled on android.")
 DEF_SWITCHES_END
 
 void PrintUsage(const std::string& executable_name);
diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index 6109d1d05a5fe..2ebd606e0fa3e 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -57,13 +57,14 @@ AndroidShellHolder::AndroidShellHolder(
 
   fml::WeakPtr<PlatformViewAndroid> weak_platform_view;
   Shell::CreateCallback<PlatformView> on_create_platform_view =
-      [is_background_view, &jni_facade, &weak_platform_view](Shell& shell) {
+      [is_background_view, &jni_facade, &weak_platform_view, use_embedded_view = settings.use_embedded_view](Shell& shell) {
         std::unique_ptr<PlatformViewAndroid> platform_view_android;
         if (is_background_view) {
           platform_view_android = std::make_unique<PlatformViewAndroid>(
               shell,                   // delegate
               shell.GetTaskRunners(),  // task runners
-              jni_facade               // JNI interop
+              jni_facade,               // JNI interop
+              use_embedded_view
           );
         } else {
           platform_view_android = std::make_unique<PlatformViewAndroid>(
@@ -71,7 +72,8 @@ AndroidShellHolder::AndroidShellHolder(
               shell.GetTaskRunners(),  // task runners
               jni_facade,              // JNI interop
               shell.GetSettings()
-                  .enable_software_rendering  // use software rendering
+                  .enable_software_rendering,  // use software rendering,
+              use_embedded_view
           );
         }
         weak_platform_view = platform_view_android->GetWeakPtr();
@@ -102,7 +104,6 @@ AndroidShellHolder::AndroidShellHolder(
     io_runner = thread_host_.io_thread->GetTaskRunner();
   }
   if (settings.use_embedded_view) {
-    FML_DLOG(ERROR) << "use_embedded_view TRUE";
     // Embedded views requires the gpu and the platform views to be the same.
     // The plan is to eventually dynamically merge the threads when there's a
     // platform view in the layer tree.
@@ -126,7 +127,6 @@ AndroidShellHolder::AndroidShellHolder(
                     on_create_rasterizer      // rasterizer create callback
       );
   } else {
-    FML_DLOG(ERROR) << "use_embedded_view FALSE";
     flutter::TaskRunners task_runners(thread_label,     // label
                                       platform_runner,  // platform
                                       gpu_runner,       // raster
diff --git a/shell/platform/android/flutter_main.cc b/shell/platform/android/flutter_main.cc
index 70fcde2868084..1493bf4f0d161 100644
--- a/shell/platform/android/flutter_main.cc
+++ b/shell/platform/android/flutter_main.cc
@@ -63,8 +63,7 @@ void FlutterMain::Init(JNIEnv* env,
                        jstring kernelPath,
                        jstring appStoragePath,
                        jstring engineCachesPath,
-                       jlong initTimeMillis,
-                       jboolean useEmbeddedView) {
+                       jlong initTimeMillis) {
   std::vector<std::string> args;
   args.push_back("flutter");
   for (auto& arg : fml::jni::StringArrayToVector(env, jargs)) {
@@ -74,10 +73,6 @@ void FlutterMain::Init(JNIEnv* env,
 
   auto settings = SettingsFromCommandLine(command_line);
 
-  // TODO(cyanlaz): Remove this when dynamic thread merging is done.
-  // https://github.com/flutter/flutter/issues/59930
-  settings.use_embedded_view = useEmbeddedView;
-
   int64_t init_time_micros = initTimeMillis * 1000;
   settings.engine_start_timestamp =
       std::chrono::microseconds(Dart_TimelineGetMicros() - init_time_micros);
@@ -171,7 +166,7 @@ bool FlutterMain::Register(JNIEnv* env) {
       {
           .name = "nativeInit",
           .signature = "(Landroid/content/Context;[Ljava/lang/String;Ljava/"
-                       "lang/String;Ljava/lang/String;Ljava/lang/String;J;Z)V",
+                       "lang/String;Ljava/lang/String;Ljava/lang/String;J)V",
           .fnPtr = reinterpret_cast<void*>(&Init),
       },
       {
diff --git a/shell/platform/android/flutter_main.h b/shell/platform/android/flutter_main.h
index 097dd9f5bee26..171800b3ec500 100644
--- a/shell/platform/android/flutter_main.h
+++ b/shell/platform/android/flutter_main.h
@@ -29,8 +29,6 @@ class FlutterMain {
 
   FlutterMain(flutter::Settings settings);
 
-  // TODO(cyanlaz): Remove `useEmbeddedView` when dynamic thread merging is done.
-  // https://github.com/flutter/flutter/issues/59930
   static void Init(JNIEnv* env,
                    jclass clazz,
                    jobject context,
@@ -38,8 +36,7 @@ class FlutterMain {
                    jstring kernelPath,
                    jstring appStoragePath,
                    jstring engineCachesPath,
-                   jlong initTimeMillis,
-                   jboolean useEmbeddedView);
+                   jlong initTimeMillis);
 
   void SetupObservatoryUriCallback(JNIEnv* env);
 
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
index 5e43047bf4789..5fb4e337c6ef5 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
@@ -110,8 +110,7 @@ public static native void nativeInit(
       @Nullable String bundlePath,
       @NonNull String appStoragePath,
       @NonNull String engineCachesPath,
-      long initTimeMillis,
-      boolean useEmbeddedView);
+      long initTimeMillis);
 
   /**
    * Prefetch the default font manager provided by SkFontMgr::RefDefault() which is a process-wide
diff --git a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
index 50f4c9ffbda8e..de52d2fed7151 100644
--- a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
+++ b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
@@ -238,6 +238,9 @@ public void ensureInitializationComplete(
       // https://github.com/flutter/flutter/issues/59930
       Bundle bundle = applicationInfo.metaData;
       boolean use_embedded_view = bundle.getBoolean("io.flutter.embedded_views_preview");
+      if (use_embedded_view) {
+        shellArgs.add("--use-embedded-view");
+      }
 
       FlutterJNI.nativeInit(
           applicationContext,
@@ -245,8 +248,7 @@ public void ensureInitializationComplete(
           kernelPath,
           result.appStoragePath,
           result.engineCachesPath,
-          initTimeMillis,
-          use_embedded_view);
+          initTimeMillis);
 
       initialized = true;
     } catch (Exception e) {
diff --git a/shell/platform/android/platform_view_android.cc b/shell/platform/android/platform_view_android.cc
index c7aaf1ef6b3a7..44df75ac0b76f 100644
--- a/shell/platform/android/platform_view_android.cc
+++ b/shell/platform/android/platform_view_android.cc
@@ -51,7 +51,8 @@ PlatformViewAndroid::PlatformViewAndroid(
     PlatformView::Delegate& delegate,
     flutter::TaskRunners task_runners,
     std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
-    bool use_software_rendering)
+    bool use_software_rendering,
+    bool use_embedded_view)
     : PlatformView(delegate, std::move(task_runners)), jni_facade_(jni_facade) {
   std::shared_ptr<AndroidContext> android_context;
   if (use_software_rendering) {
@@ -70,7 +71,7 @@ PlatformViewAndroid::PlatformViewAndroid(
   FML_CHECK(android_context && android_context->IsValid())
       << "Could not create an Android context.";
 
-  android_surface_ = SurfaceFactory(std::move(android_context), jni_facade);
+  android_surface_ = SurfaceFactory(std::move(android_context), jni_facade, use_embedded_view);
   FML_CHECK(android_surface_ && android_surface_->IsValid())
       << "Could not create an OpenGL, Vulkan or Software surface to setup "
          "rendering.";
@@ -79,7 +80,8 @@ PlatformViewAndroid::PlatformViewAndroid(
 PlatformViewAndroid::PlatformViewAndroid(
     PlatformView::Delegate& delegate,
     flutter::TaskRunners task_runners,
-    std::shared_ptr<PlatformViewAndroidJNI> jni_facade)
+    std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
+    bool use_embedded_view)
     : PlatformView(delegate, std::move(task_runners)),
       jni_facade_(jni_facade) {}
 
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index c0b6a1d79a4d8..7e52c57911be0 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -29,13 +29,15 @@ class PlatformViewAndroid final : public PlatformView {
   // background execution.
   PlatformViewAndroid(PlatformView::Delegate& delegate,
                       flutter::TaskRunners task_runners,
-                      std::shared_ptr<PlatformViewAndroidJNI> jni_facade);
+                      std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
+                      bool use_embedded_view);
 
   // Creates a PlatformViewAndroid with a rendering surface.
   PlatformViewAndroid(PlatformView::Delegate& delegate,
                       flutter::TaskRunners task_runners,
                       std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
-                      bool use_software_rendering);
+                      bool use_software_rendering,
+                      bool use_embedded_view);
 
   ~PlatformViewAndroid() override;
 

From 994d91f87751e4109d00355056e2de13560e83a0 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 14:00:59 -0700
Subject: [PATCH 08/13] cleanup

---
 shell/platform/android/android_shell_holder.cc            | 8 +++-----
 .../external_view_embedder/external_view_embedder.h       | 1 +
 shell/platform/android/platform_view_android.cc           | 8 +++-----
 shell/platform/android/platform_view_android.h            | 7 +++----
 4 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index 2ebd606e0fa3e..5da2b2af6b7f9 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -57,14 +57,13 @@ AndroidShellHolder::AndroidShellHolder(
 
   fml::WeakPtr<PlatformViewAndroid> weak_platform_view;
   Shell::CreateCallback<PlatformView> on_create_platform_view =
-      [is_background_view, &jni_facade, &weak_platform_view, use_embedded_view = settings.use_embedded_view](Shell& shell) {
+      [is_background_view, &jni_facade, &weak_platform_view](Shell& shell) {
         std::unique_ptr<PlatformViewAndroid> platform_view_android;
         if (is_background_view) {
           platform_view_android = std::make_unique<PlatformViewAndroid>(
               shell,                   // delegate
               shell.GetTaskRunners(),  // task runners
-              jni_facade,               // JNI interop
-              use_embedded_view
+              jni_facade              // JNI interop
           );
         } else {
           platform_view_android = std::make_unique<PlatformViewAndroid>(
@@ -72,8 +71,7 @@ AndroidShellHolder::AndroidShellHolder(
               shell.GetTaskRunners(),  // task runners
               jni_facade,              // JNI interop
               shell.GetSettings()
-                  .enable_software_rendering,  // use software rendering,
-              use_embedded_view
+                  .enable_software_rendering  // use software rendering,
           );
         }
         weak_platform_view = platform_view_android->GetWeakPtr();
diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.h b/shell/platform/android/external_view_embedder/external_view_embedder.h
index 41b6e68f1155d..e25bdc358cb71 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder.h
+++ b/shell/platform/android/external_view_embedder/external_view_embedder.h
@@ -26,6 +26,7 @@ namespace flutter {
 ///
 class AndroidExternalViewEmbedder final : public ExternalViewEmbedder {
  public:
+
   AndroidExternalViewEmbedder(
       std::shared_ptr<AndroidContext> android_context,
       std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
diff --git a/shell/platform/android/platform_view_android.cc b/shell/platform/android/platform_view_android.cc
index 44df75ac0b76f..c7aaf1ef6b3a7 100644
--- a/shell/platform/android/platform_view_android.cc
+++ b/shell/platform/android/platform_view_android.cc
@@ -51,8 +51,7 @@ PlatformViewAndroid::PlatformViewAndroid(
     PlatformView::Delegate& delegate,
     flutter::TaskRunners task_runners,
     std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
-    bool use_software_rendering,
-    bool use_embedded_view)
+    bool use_software_rendering)
     : PlatformView(delegate, std::move(task_runners)), jni_facade_(jni_facade) {
   std::shared_ptr<AndroidContext> android_context;
   if (use_software_rendering) {
@@ -71,7 +70,7 @@ PlatformViewAndroid::PlatformViewAndroid(
   FML_CHECK(android_context && android_context->IsValid())
       << "Could not create an Android context.";
 
-  android_surface_ = SurfaceFactory(std::move(android_context), jni_facade, use_embedded_view);
+  android_surface_ = SurfaceFactory(std::move(android_context), jni_facade);
   FML_CHECK(android_surface_ && android_surface_->IsValid())
       << "Could not create an OpenGL, Vulkan or Software surface to setup "
          "rendering.";
@@ -80,8 +79,7 @@ PlatformViewAndroid::PlatformViewAndroid(
 PlatformViewAndroid::PlatformViewAndroid(
     PlatformView::Delegate& delegate,
     flutter::TaskRunners task_runners,
-    std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
-    bool use_embedded_view)
+    std::shared_ptr<PlatformViewAndroidJNI> jni_facade)
     : PlatformView(delegate, std::move(task_runners)),
       jni_facade_(jni_facade) {}
 
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index 7e52c57911be0..2e1a76c5467f6 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -29,15 +29,13 @@ class PlatformViewAndroid final : public PlatformView {
   // background execution.
   PlatformViewAndroid(PlatformView::Delegate& delegate,
                       flutter::TaskRunners task_runners,
-                      std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
-                      bool use_embedded_view);
+                      std::shared_ptr<PlatformViewAndroidJNI> jni_facade);
 
   // Creates a PlatformViewAndroid with a rendering surface.
   PlatformViewAndroid(PlatformView::Delegate& delegate,
                       flutter::TaskRunners task_runners,
                       std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
-                      bool use_software_rendering,
-                      bool use_embedded_view);
+                      bool use_software_rendering);
 
   ~PlatformViewAndroid() override;
 
@@ -77,6 +75,7 @@ class PlatformViewAndroid final : public PlatformView {
       const fml::jni::JavaObjectWeakGlobalRef& surface_texture);
 
  private:
+
   const std::shared_ptr<PlatformViewAndroidJNI> jni_facade_;
 
   std::unique_ptr<AndroidSurface> android_surface_;

From 9bdbd7f162ce7d40e5fb41af82ef634088905f52 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 14:51:17 -0700
Subject: [PATCH 09/13] no external view embedder if flag not set

---
 shell/platform/android/android_shell_holder.cc     | 4 ++++
 shell/platform/android/android_shell_holder.h      | 9 +++++++++
 shell/platform/android/android_surface_gl.cc       | 4 ++++
 shell/platform/android/android_surface_software.cc | 4 ++++
 shell/platform/android/platform_view_android.h     | 1 -
 shell/platform/android/surface/android_surface.h   | 1 +
 6 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index 5da2b2af6b7f9..2300e2f44f5c6 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -28,6 +28,8 @@ static WindowData GetDefaultWindowData() {
   return window_data;
 }
 
+bool AndroidShellHolder::use_embedded_view;
+
 AndroidShellHolder::AndroidShellHolder(
     flutter::Settings settings,
     std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
@@ -102,6 +104,7 @@ AndroidShellHolder::AndroidShellHolder(
     io_runner = thread_host_.io_thread->GetTaskRunner();
   }
   if (settings.use_embedded_view) {
+    use_embedded_view = true;
     // Embedded views requires the gpu and the platform views to be the same.
     // The plan is to eventually dynamically merge the threads when there's a
     // platform view in the layer tree.
@@ -125,6 +128,7 @@ AndroidShellHolder::AndroidShellHolder(
                     on_create_rasterizer      // rasterizer create callback
       );
   } else {
+    use_embedded_view = false;
     flutter::TaskRunners task_runners(thread_label,     // label
                                       platform_runner,  // platform
                                       gpu_runner,       // raster
diff --git a/shell/platform/android/android_shell_holder.h b/shell/platform/android/android_shell_holder.h
index 107e93f18672a..faddbc54346e2 100644
--- a/shell/platform/android/android_shell_holder.h
+++ b/shell/platform/android/android_shell_holder.h
@@ -20,7 +20,16 @@
 namespace flutter {
 
 class AndroidShellHolder {
+
  public:
+
+  // Whether the application sets to use embedded_view view
+  // `io.flutter.embedded_views_preview` flag. This can be static because it is determined by
+  // the application and it is safe when there are multiple `AndroidSurface`s.
+  // TODO(cyanglaz): remove this when dynamic thread merging is enabled on android.
+  // https://github.com/flutter/flutter/issues/59930
+  static bool use_embedded_view;
+
   AndroidShellHolder(flutter::Settings settings,
                      std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
                      bool is_background_view);
diff --git a/shell/platform/android/android_surface_gl.cc b/shell/platform/android/android_surface_gl.cc
index f4bd9e6747907..c8cc3d2d1183e 100644
--- a/shell/platform/android/android_surface_gl.cc
+++ b/shell/platform/android/android_surface_gl.cc
@@ -8,6 +8,7 @@
 
 #include "flutter/fml/logging.h"
 #include "flutter/fml/memory/ref_ptr.h"
+#include "flutter/shell/platform/android/android_shell_holder.h"
 
 namespace flutter {
 
@@ -122,6 +123,9 @@ intptr_t AndroidSurfaceGL::GLContextFBO() const {
 
 // |GPUSurfaceGLDelegate|
 ExternalViewEmbedder* AndroidSurfaceGL::GetExternalViewEmbedder() {
+  if (!AndroidShellHolder::use_embedded_view) {
+    return nullptr;
+  }
   return external_view_embedder_.get();
 }
 
diff --git a/shell/platform/android/android_surface_software.cc b/shell/platform/android/android_surface_software.cc
index 7face67038d0a..3bc52e317279a 100644
--- a/shell/platform/android/android_surface_software.cc
+++ b/shell/platform/android/android_surface_software.cc
@@ -11,6 +11,7 @@
 #include "flutter/fml/platform/android/jni_weak_ref.h"
 #include "flutter/fml/platform/android/scoped_java_ref.h"
 #include "flutter/fml/trace_event.h"
+#include "flutter/shell/platform/android/android_shell_holder.h"
 #include "flutter/shell/platform/android/jni/platform_view_android_jni.h"
 
 namespace flutter {
@@ -145,6 +146,9 @@ bool AndroidSurfaceSoftware::PresentBackingStore(
 
 // |GPUSurfaceSoftwareDelegate|
 ExternalViewEmbedder* AndroidSurfaceSoftware::GetExternalViewEmbedder() {
+  if (!AndroidShellHolder::use_embedded_view) {
+    return nullptr;
+  }
   return external_view_embedder_.get();
 }
 
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index 2e1a76c5467f6..39a0ce19380a4 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -118,7 +118,6 @@ class PlatformViewAndroid final : public PlatformView {
 
   FML_DISALLOW_COPY_AND_ASSIGN(PlatformViewAndroid);
 };
-
 }  // namespace flutter
 
 #endif  // SHELL_PLATFORM_ANDROID_PLATFORM_VIEW_ANDROID_H_
diff --git a/shell/platform/android/surface/android_surface.h b/shell/platform/android/surface/android_surface.h
index 26604f4ff7717..928127e1364cf 100644
--- a/shell/platform/android/surface/android_surface.h
+++ b/shell/platform/android/surface/android_surface.h
@@ -16,6 +16,7 @@ namespace flutter {
 
 class AndroidSurface {
  public:
+
   using Factory = std::function<std::unique_ptr<AndroidSurface>(
       std::shared_ptr<AndroidContext> android_context,
       std::shared_ptr<PlatformViewAndroidJNI> jni_facade)>;

From ddd34bb4243b8815f869cd88fb5e17d346b8131f Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Tue, 23 Jun 2020 14:54:23 -0700
Subject: [PATCH 10/13] cleanup

---
 shell/platform/android/android_shell_holder.cc                | 4 ++--
 .../android/external_view_embedder/external_view_embedder.h   | 1 -
 shell/platform/android/platform_view_android.h                | 1 -
 shell/platform/android/surface/android_surface.h              | 1 -
 4 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index 2300e2f44f5c6..c12623f33a7da 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -65,7 +65,7 @@ AndroidShellHolder::AndroidShellHolder(
           platform_view_android = std::make_unique<PlatformViewAndroid>(
               shell,                   // delegate
               shell.GetTaskRunners(),  // task runners
-              jni_facade              // JNI interop
+              jni_facade               // JNI interop
           );
         } else {
           platform_view_android = std::make_unique<PlatformViewAndroid>(
@@ -73,7 +73,7 @@ AndroidShellHolder::AndroidShellHolder(
               shell.GetTaskRunners(),  // task runners
               jni_facade,              // JNI interop
               shell.GetSettings()
-                  .enable_software_rendering  // use software rendering,
+                  .enable_software_rendering  // use software rendering
           );
         }
         weak_platform_view = platform_view_android->GetWeakPtr();
diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.h b/shell/platform/android/external_view_embedder/external_view_embedder.h
index e25bdc358cb71..41b6e68f1155d 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder.h
+++ b/shell/platform/android/external_view_embedder/external_view_embedder.h
@@ -26,7 +26,6 @@ namespace flutter {
 ///
 class AndroidExternalViewEmbedder final : public ExternalViewEmbedder {
  public:
-
   AndroidExternalViewEmbedder(
       std::shared_ptr<AndroidContext> android_context,
       std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index 39a0ce19380a4..c7b22fb17070e 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -75,7 +75,6 @@ class PlatformViewAndroid final : public PlatformView {
       const fml::jni::JavaObjectWeakGlobalRef& surface_texture);
 
  private:
-
   const std::shared_ptr<PlatformViewAndroidJNI> jni_facade_;
 
   std::unique_ptr<AndroidSurface> android_surface_;
diff --git a/shell/platform/android/surface/android_surface.h b/shell/platform/android/surface/android_surface.h
index 928127e1364cf..26604f4ff7717 100644
--- a/shell/platform/android/surface/android_surface.h
+++ b/shell/platform/android/surface/android_surface.h
@@ -16,7 +16,6 @@ namespace flutter {
 
 class AndroidSurface {
  public:
-
   using Factory = std::function<std::unique_ptr<AndroidSurface>(
       std::shared_ptr<AndroidContext> android_context,
       std::shared_ptr<PlatformViewAndroidJNI> jni_facade)>;

From a37f942dc7475016540e2827b2f78795c4228527 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Wed, 24 Jun 2020 13:40:54 -0700
Subject: [PATCH 11/13] review fixes

---
 common/settings.h                                             | 2 +-
 shell/platform/android/android_shell_holder.h                 | 1 -
 shell/platform/android/platform_view_android.h                | 1 +
 testing/scenario_app/android/app/src/main/AndroidManifest.xml | 3 +++
 4 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/common/settings.h b/common/settings.h
index ea4970747fbe9..25af94a806438 100644
--- a/common/settings.h
+++ b/common/settings.h
@@ -213,7 +213,7 @@ struct Settings {
   /// to log a timeline event that tracks the latency of engine startup.
   std::chrono::microseconds engine_start_timestamp = {};
 
-  /// Does the application claim that it uses the android embedded view for platform views.
+  /// Whether the application claims that it uses the android embedded view for platform views.
   ///
   /// A `true` value will result the raster task runner always run on the platform thread.
   // TODO(cyanlaz): Remove this when dynamic thread merging is done.
diff --git a/shell/platform/android/android_shell_holder.h b/shell/platform/android/android_shell_holder.h
index faddbc54346e2..4bc2eb5999b72 100644
--- a/shell/platform/android/android_shell_holder.h
+++ b/shell/platform/android/android_shell_holder.h
@@ -20,7 +20,6 @@
 namespace flutter {
 
 class AndroidShellHolder {
-
  public:
 
   // Whether the application sets to use embedded_view view
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index c7b22fb17070e..55d40522c8ca8 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -116,6 +116,7 @@ class PlatformViewAndroid final : public PlatformView {
   void FireFirstFrameCallback();
 
   FML_DISALLOW_COPY_AND_ASSIGN(PlatformViewAndroid);
+
 };
 }  // namespace flutter
 
diff --git a/testing/scenario_app/android/app/src/main/AndroidManifest.xml b/testing/scenario_app/android/app/src/main/AndroidManifest.xml
index 65ff9e909329b..a7416851ccd0d 100644
--- a/testing/scenario_app/android/app/src/main/AndroidManifest.xml
+++ b/testing/scenario_app/android/app/src/main/AndroidManifest.xml
@@ -28,6 +28,9 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        <meta-data
+            android:name="io.flutter.embedded_views_preview"
+            android:value="true" />
     </application>
 
     <uses-permission android:name="android.permission.INTERNET" />

From 0f922f82d41fdcecc08801bf2bf60a8b4b974d15 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Wed, 24 Jun 2020 13:48:14 -0700
Subject: [PATCH 12/13] formatting

---
 common/settings.h                             |  6 ++--
 shell/common/switches.cc                      |  3 +-
 shell/common/switches.h                       |  6 ++--
 .../platform/android/android_shell_holder.cc  | 34 +++++++++----------
 shell/platform/android/android_shell_holder.h | 10 +++---
 .../platform/android/platform_view_android.h  |  1 -
 6 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/common/settings.h b/common/settings.h
index 25af94a806438..bf615379637e5 100644
--- a/common/settings.h
+++ b/common/settings.h
@@ -213,9 +213,11 @@ struct Settings {
   /// to log a timeline event that tracks the latency of engine startup.
   std::chrono::microseconds engine_start_timestamp = {};
 
-  /// Whether the application claims that it uses the android embedded view for platform views.
+  /// Whether the application claims that it uses the android embedded view for
+  /// platform views.
   ///
-  /// A `true` value will result the raster task runner always run on the platform thread.
+  /// A `true` value will result the raster task runner always run on the
+  /// platform thread.
   // TODO(cyanlaz): Remove this when dynamic thread merging is done.
   // https://github.com/flutter/flutter/issues/59930
   bool use_embedded_view = false;
diff --git a/shell/common/switches.cc b/shell/common/switches.cc
index 235a5148410d3..34c4c4ee56f46 100644
--- a/shell/common/switches.cc
+++ b/shell/common/switches.cc
@@ -227,7 +227,8 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
                                                             : "127.0.0.1";
   }
 
-  settings.use_embedded_view = command_line.HasOption(FlagForSwitch(Switch::UseEmbeddedView));
+  settings.use_embedded_view =
+      command_line.HasOption(FlagForSwitch(Switch::UseEmbeddedView));
 
   // Set Observatory Port
   if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryPort))) {
diff --git a/shell/common/switches.h b/shell/common/switches.h
index 62d0683ae866d..8506bc7e72496 100644
--- a/shell/common/switches.h
+++ b/shell/common/switches.h
@@ -194,8 +194,10 @@ DEF_SWITCH(
 DEF_SWITCH(UseEmbeddedView,
            "use-embedded-view",
            "Whether an android application uses embedded views."
-           "This is a temporary flag to make the raster task runner runs on the platform thread."
-           "This flag should be removed once the dynamic thread merging is enabled on android.")
+           "This is a temporary flag to make the raster task runner runs on "
+           "the platform thread."
+           "This flag should be removed once the dynamic thread merging is "
+           "enabled on android.")
 DEF_SWITCHES_END
 
 void PrintUsage(const std::string& executable_name);
diff --git a/shell/platform/android/android_shell_holder.cc b/shell/platform/android/android_shell_holder.cc
index c12623f33a7da..c9667dcb7edf3 100644
--- a/shell/platform/android/android_shell_holder.cc
+++ b/shell/platform/android/android_shell_holder.cc
@@ -108,25 +108,25 @@ AndroidShellHolder::AndroidShellHolder(
     // Embedded views requires the gpu and the platform views to be the same.
     // The plan is to eventually dynamically merge the threads when there's a
     // platform view in the layer tree.
-    // For now we use a fixed thread configuration with the same thread used as the
-    // gpu and platform task runner.
-    // TODO(amirh/chinmaygarde): remove this, and dynamically change the thread configuration.
-    // https://github.com/flutter/flutter/issues/23975
+    // For now we use a fixed thread configuration with the same thread used as
+    // the gpu and platform task runner.
+    // TODO(amirh/chinmaygarde): remove this, and dynamically change the thread
+    // configuration. https://github.com/flutter/flutter/issues/23975
     // https://github.com/flutter/flutter/issues/59930
     flutter::TaskRunners task_runners(thread_label,     // label
                                       platform_runner,  // platform
-                                      platform_runner,       // raster
+                                      platform_runner,  // raster
                                       ui_runner,        // ui
                                       io_runner         // io
     );
 
     shell_ =
-      Shell::Create(task_runners,             // task runners
-                    GetDefaultWindowData(),   // window data
-                    settings_,                // settings
-                    on_create_platform_view,  // platform view create callback
-                    on_create_rasterizer      // rasterizer create callback
-      );
+        Shell::Create(task_runners,             // task runners
+                      GetDefaultWindowData(),   // window data
+                      settings_,                // settings
+                      on_create_platform_view,  // platform view create callback
+                      on_create_rasterizer      // rasterizer create callback
+        );
   } else {
     use_embedded_view = false;
     flutter::TaskRunners task_runners(thread_label,     // label
@@ -137,12 +137,12 @@ AndroidShellHolder::AndroidShellHolder(
     );
 
     shell_ =
-      Shell::Create(task_runners,             // task runners
-                    GetDefaultWindowData(),   // window data
-                    settings_,                // settings
-                    on_create_platform_view,  // platform view create callback
-                    on_create_rasterizer      // rasterizer create callback
-      );
+        Shell::Create(task_runners,             // task runners
+                      GetDefaultWindowData(),   // window data
+                      settings_,                // settings
+                      on_create_platform_view,  // platform view create callback
+                      on_create_rasterizer      // rasterizer create callback
+        );
   }
 
   platform_view_ = weak_platform_view;
diff --git a/shell/platform/android/android_shell_holder.h b/shell/platform/android/android_shell_holder.h
index 4bc2eb5999b72..6fb6695801733 100644
--- a/shell/platform/android/android_shell_holder.h
+++ b/shell/platform/android/android_shell_holder.h
@@ -21,12 +21,12 @@ namespace flutter {
 
 class AndroidShellHolder {
  public:
-
   // Whether the application sets to use embedded_view view
-  // `io.flutter.embedded_views_preview` flag. This can be static because it is determined by
-  // the application and it is safe when there are multiple `AndroidSurface`s.
-  // TODO(cyanglaz): remove this when dynamic thread merging is enabled on android.
-  // https://github.com/flutter/flutter/issues/59930
+  // `io.flutter.embedded_views_preview` flag. This can be static because it is
+  // determined by the application and it is safe when there are multiple
+  // `AndroidSurface`s.
+  // TODO(cyanglaz): remove this when dynamic thread merging is enabled on
+  // android. https://github.com/flutter/flutter/issues/59930
   static bool use_embedded_view;
 
   AndroidShellHolder(flutter::Settings settings,
diff --git a/shell/platform/android/platform_view_android.h b/shell/platform/android/platform_view_android.h
index 55d40522c8ca8..c7b22fb17070e 100644
--- a/shell/platform/android/platform_view_android.h
+++ b/shell/platform/android/platform_view_android.h
@@ -116,7 +116,6 @@ class PlatformViewAndroid final : public PlatformView {
   void FireFirstFrameCallback();
 
   FML_DISALLOW_COPY_AND_ASSIGN(PlatformViewAndroid);
-
 };
 }  // namespace flutter
 

From 66a2f6fe88be37fd21589164f00bcb0a87bc0c44 Mon Sep 17 00:00:00 2001
From: Chris Yang <ychris@google.com>
Date: Wed, 24 Jun 2020 14:11:34 -0700
Subject: [PATCH 13/13] null check

---
 .../io/flutter/embedding/engine/loader/FlutterLoader.java | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
index de52d2fed7151..9156a64ef061e 100644
--- a/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
+++ b/shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java
@@ -237,9 +237,11 @@ public void ensureInitializationComplete(
       // TODO(cyanlaz): Remove this when dynamic thread merging is done.
       // https://github.com/flutter/flutter/issues/59930
       Bundle bundle = applicationInfo.metaData;
-      boolean use_embedded_view = bundle.getBoolean("io.flutter.embedded_views_preview");
-      if (use_embedded_view) {
-        shellArgs.add("--use-embedded-view");
+      if (bundle != null) {
+        boolean use_embedded_view = bundle.getBoolean("io.flutter.embedded_views_preview");
+        if (use_embedded_view) {
+          shellArgs.add("--use-embedded-view");
+        }
       }
 
       FlutterJNI.nativeInit(