Do full repaint after removing platform view

Author: knopp

flow/diff_context.cc

@@ -162,10 +162,6 @@ bool DiffContext::PushCullRect(const SkRect& clip) {
   return !state_.matrix_clip.device_cull_rect().isEmpty();
 }
 
-void DiffContext::ForceFullRepaint() {
-  damage_ = SkRect::MakeIWH(frame_size_.width(), frame_size_.height());
-}
-
 SkMatrix DiffContext::GetTransform3x3() const {
   return state_.matrix_clip.matrix_3x3();
 }
@@ -207,6 +203,12 @@ void DiffContext::AddLayerBounds(const SkRect& rect) {
   }
 }
 
+void DiffContext::RepaintEntireFrame() {
+  auto frame_rect = SkRect::MakeIWH(frame_size_.width(), frame_size_.height());
+  rects_->push_back(frame_rect);
+  AddDamage(frame_rect);
+}
+
 void DiffContext::MarkSubtreeHasVolatileLayer() {
   // Set the has_texture flag on current state and all parent states. That
   // way we'll know that we can't skip diff for retained layers because

flow/diff_context.h

@@ -77,9 +77,6 @@ class DiffContext {
   // Pushes cull rect for current subtree
   bool PushCullRect(const SkRect& clip);
 
-  // Marks entire frame as dirty.
-  void ForceFullRepaint();
-
   // Function that adjusts layer bounds (in device coordinates) depending
   // on filter.
   using FilterBoundsAdjustment = std::function<SkRect(SkRect)>;
@@ -119,6 +116,9 @@ class DiffContext {
   // coordinates.
   void AddLayerBounds(const SkRect& rect);
 
+  // Marks entire frame as dirty.
+  void RepaintEntireFrame();
+
   // Add entire paint region of retained layer for current subtree. This can
   // only be used in subtrees that are not dirty, otherwise ancestor transforms
   // or clips may result in different paint region.

flow/layers/platform_view_layer.cc

@@ -17,11 +17,11 @@ void PlatformViewLayer::Diff(DiffContext* context, const Layer* old_layer) {
   DiffContext::AutoSubtreeRestore subtree(context);
   // Ensure that Diff is called again even if this layer is in retained subtree.
   context->MarkSubtreeHasVolatileLayer();
-  // It is not necessary to track the actual paint region for the layer due to
-  // forced full repaint below, but the paint region carries the volatile layer
-  // flag.
+  // Partial repaint is disabled when platform view is present. This will also
+  // set whole frame as the layer paint region, which will ensure full repaint
+  // when the layer is removed.
+  context->RepaintEntireFrame();
   context->SetLayerPaintRegion(this, context->CurrentSubtreeRegion());
-  context->ForceFullRepaint();
 }
 
 void PlatformViewLayer::Preroll(PrerollContext* context) {