[VSync Queue] Flush input in CommitComplete()

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 The Chromium 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 CC_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <stddef.h>
 
 #include <bitset>
@@ skipping 70 matching lines @@
 using BeginFrameCallbackList = std::vector<base::Closure>;
 
 enum class GpuRasterizationStatus {
   ON,
   ON_FORCED,
   OFF_DEVICE,
   OFF_VIEWPORT,
   MSAA_CONTENT,
 };
 
+enum class ImplThreadPhase {
+  IDLE,
+  INSIDE_IMPL_FRAME,
+};
+
 // LayerTreeHost->Proxy callback interface.
 class LayerTreeHostImplClient {
  public:
   virtual void DidLoseCompositorFrameSinkOnImplThread() = 0;
   virtual void SetBeginFrameSource(BeginFrameSource* source) = 0;
   virtual void DidReceiveCompositorFrameAckOnImplThread() = 0;
   virtual void OnCanDrawStateChanged(bool can_draw) = 0;
   virtual void NotifyReadyToActivate() = 0;
   virtual void NotifyReadyToDraw() = 0;
   // Please call these 2 functions through
@@ skipping 762 matching lines @@
   // begin main frame. These callbacks must only be called on the main thread.
   std::vector<base::Closure> completed_image_decode_callbacks_;
 
   // These are used to transfer usage of touch and wheel scrolls to the main
   // thread.
   bool has_scrolled_by_wheel_;
   bool has_scrolled_by_touch_;
 
   bool touchpad_and_wheel_scroll_latching_enabled_;
 
+  ImplThreadPhase impl_thread_phase_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_