Add second copy request after screen rotation to flatten the layers in animation.

ash/rotator/screen_rotation_animator.h

Index: ash/rotator/screen_rotation_animator.h
diff --git a/ash/rotator/screen_rotation_animator.h b/ash/rotator/screen_rotation_animator.h
index b541106e88030c68a5217cc03451e46268688eae..67ec82c9ca1bb282957c21f7c4637140c93675d6 100644
--- a/ash/rotator/screen_rotation_animator.h
+++ b/ash/rotator/screen_rotation_animator.h
@@ -11,10 +11,16 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "cc/output/copy_output_request.h"
 #include "ui/display/display.h"
 
+namespace cc {
+class CopyOutputResult;
+}  // namespace cc
+
 namespace ui {
 class AnimationMetricsReporter;
+class CallbackLayerAnimationObserver;
 class Layer;
 class LayerTreeOwner;
 }  // namespace ui
@@ -59,7 +65,42 @@ class ASH_EXPORT ScreenRotationAnimator {
   friend class ash::test::ScreenRotationAnimatorTestApi;
   struct ScreenRotationRequest;
 
-  // Set the screen orientation to |new_rotation| and animate the change. The
+  void StartRotationAnimation(
+      std::unique_ptr<ScreenRotationRequest> rotation_request);
+
+  // The fallback plan if copy output request failed, such as the request is
+  // canceled.
+  void StartSlowAnimation(
+      std::unique_ptr<ScreenRotationRequest> rotation_request);
+
+  // This is an asynchronous call to request copy output of root layer.
+  void RequestCopyRootLayerByName(
+      const std::string& layer_name,
+      const cc::CopyOutputRequest::CopyOutputRequestCallback& callback);
+
+  // The callback for the first CopyOutputRequest before screen rotation.
+  void OnRootLayerCopiedBeforeRotation(
+      std::unique_ptr<ScreenRotationRequest> rotation_request,
+      std::unique_ptr<cc::CopyOutputResult> result);
+
+  // The callback for the second CopyOutputRequest after screen rotation.
+  void OnRootLayerCopiedAfterRotation(
+      std::unique_ptr<ScreenRotationRequest> rotation_request,
+      std::unique_ptr<cc::CopyOutputResult> result);
+
+  // Recreates all |root_window| layers.
+  void CreateOldLayerTree();
+
+  // Creates a copy layer from cc::CopyOutputResult |result|.
+  std::unique_ptr<ui::LayerTreeOwner> CopyLayerTree(
+      const std::string& layer_name,
+      std::unique_ptr<cc::CopyOutputResult> result);
+
+  void SetRotation(const display::Display::Rotation& new_rotation,
+                   const display::Display::Rotation& old_rotation,
+                   const display::Display::RotationSource& source);
+
+  // Sets the screen orientation to |new_rotation| and animate the change. The
   // animation will rotate the initial orientation's layer towards the new
   // orientation through |rotation_degrees| while fading out, and the new
   // orientation's layer will be rotated in to the |new_orientation| through
@@ -79,6 +120,7 @@ class ASH_EXPORT ScreenRotationAnimator {
   base::ObserverList<ScreenRotationAnimatorObserver>
       screen_rotation_animator_observers_;
   std::unique_ptr<ui::LayerTreeOwner> old_layer_tree_owner_;
+  std::unique_ptr<ui::LayerTreeOwner> new_layer_tree_owner_;
   std::unique_ptr<ScreenRotationRequest> last_pending_request_;
   base::WeakPtrFactory<ScreenRotationAnimator> weak_factory_;