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 1852033b9e6b5c8aff54bd83d0a14275daf44adf..a5c26b16c4e12b280cc373d58642c53cfacb6e6d 100644
--- a/ash/rotator/screen_rotation_animator.h
+++ b/ash/rotator/screen_rotation_animator.h
@@ -14,7 +14,12 @@
 #include "base/observer_list.h"
 #include "ui/display/display.h"
 
+namespace aura {
+class Window;
+}  // namesapce aura
+
 namespace cc {
+class CopyOutputRequest;
 class CopyOutputResult;
 }  // namespace cc
 
@@ -64,16 +69,22 @@ class ASH_EXPORT ScreenRotationAnimator {
   using CopyCallback =
       base::Callback<void(std::unique_ptr<cc::CopyOutputResult> result)>;
   struct ScreenRotationRequest {
-    ScreenRotationRequest(display::Display::Rotation to_rotation,
+    ScreenRotationRequest(display::Display::Rotation from_rotation,
+                          display::Display::Rotation to_rotation,
                           display::Display::RotationSource from_source)
-        : new_rotation(to_rotation), source(from_source) {}
+        : old_rotation(from_rotation),
+          new_rotation(to_rotation),
+          source(from_source) {}
+    display::Display::Rotation old_rotation;
     display::Display::Rotation new_rotation;
     display::Display::RotationSource source;
   };
 
   // This function can be overridden in unit test to test removing external
   // display.
-  virtual CopyCallback CreateAfterCopyCallback(
+  virtual CopyCallback CreateAfterCopyCallbackBeforeRotation(
+      std::unique_ptr<ScreenRotationRequest> rotation_request);
+  virtual CopyCallback CreateAfterCopyCallbackAfterRotation(
       std::unique_ptr<ScreenRotationRequest> rotation_request);
 
  private:
@@ -82,20 +93,38 @@ class ASH_EXPORT ScreenRotationAnimator {
   void StartRotationAnimation(
       std::unique_ptr<ScreenRotationRequest> rotation_request);
 
-  // This is an asynchronous call to request copy output of root layer.
-  void RequestCopyRootLayerAndAnimateRotation(
+  // The fallback to slow animation if copy output request cancled or failed.
+  void StartSlowAnimation(
       std::unique_ptr<ScreenRotationRequest> rotation_request);
 
-  // The callback in |RequestCopyRootLayerAndAnimateRotation()|.
-  void OnRootLayerCopiedBeforeRotation(
+  // A wrapper to call |display_manager| to set screen rotation and rotate the
+  // |old_layer_tree| to the |old_rotation|.
+  void SetRotation(display::Display::Rotation new_rotation,
+                   display::Display::Rotation old_rotation,
+                   display::Display::RotationSource source);
+
+  // This is an asynchronous call to request copy output of root layer.
+  void RequestCopyScreenRotationContainerLayer(
+      std::unique_ptr<cc::CopyOutputRequest> copy_output_request);
+
+  // The callback in |RequestCopyScreenRotationContainerLayer()| before screen
+  // rotation.
+  void OnScreenRotationContainerLayerCopiedBeforeRotation(
       std::unique_ptr<ScreenRotationRequest> rotation_request,
       std::unique_ptr<cc::CopyOutputResult> result);
 
-  // Recreates all |root_window| layers.
+  // The callback in |RequestCopyScreenRotationContainerLayer()| after screen
+  // rotation.
+  void OnScreenRotationContainerLayerCopiedAfterRotation(
+      std::unique_ptr<ScreenRotationRequest> rotation_request,
+      std::unique_ptr<cc::CopyOutputResult> result);
+
+  // Recreates all |root_window| layers and their layer tree owner.
   void CreateOldLayerTree();
 
-  // Requests a copy of |root_window| root layer output.
-  void CopyOldLayerTree(std::unique_ptr<cc::CopyOutputResult> result);
+  // Creates a new layer and its layer tree owner from |CopyOutputResult|.
+  std::unique_ptr<ui::LayerTreeOwner> CopyLayerTree(
+      std::unique_ptr<cc::CopyOutputResult> result);
 
   // Note: Only call this function when the |old_layer_tree_owner_| is set up
   // properly.
@@ -119,7 +148,11 @@ 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_;
+  bool has_switch_ash_enable_smooth_screen_rotation_;
+  ui::Layer* screen_rotation_container_layer_;
+  aura::Window* root_window_;
   base::WeakPtrFactory<ScreenRotationAnimator> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenRotationAnimator);