[VSync Queue] Flush input in CommitComplete()

cc/trees/layer_tree_host_impl.cc

 // 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.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1892 matching lines @@
     SetNeedsRedraw();
   }
 
   if (input_handler_client_)
     input_handler_client_->DeliverInputForBeginFrame();
 
   Animate();
 
   for (auto* it : video_frame_controllers_)
     it->OnBeginFrame(args);
+
+  input_handler_state_ = InputHandlerState::INSIDE_IMPL_FRAME;
 }
 
 void LayerTreeHostImpl::DidFinishImplFrame() {
+  input_handler_state_ = InputHandlerState::IDLE;

[chongz, 2017/04/27 16:19:47]

Is this the right place, or should I put it in the start of
|LayerTreeHostImpl::DrawLayers()|?

   current_begin_frame_tracker_.Finish();
   decoded_image_tracker_.NotifyFrameFinished();
 }
 
 void LayerTreeHostImpl::UpdateViewportContainerSizes() {
   LayerImpl* inner_container = active_tree_->InnerViewportContainerLayer();
   LayerImpl* outer_container = active_tree_->OuterViewportContainerLayer();
 
   if (!inner_container)
     return;
@@ skipping 605 matching lines @@
   return active_tree_->CurrentBrowserControlsShownRatio();
 }
 
 void LayerTreeHostImpl::BindToClient(InputHandlerClient* client,
                                      bool wheel_scroll_latching_enabled) {
   DCHECK(input_handler_client_ == NULL);
   input_handler_client_ = client;
   touchpad_and_wheel_scroll_latching_enabled_ = wheel_scroll_latching_enabled;
 }
 
+InputHandler::InputHandlerState LayerTreeHostImpl::GetInputHandlerState()
+    const {
+  return input_handler_state_;
+};
+
 InputHandler::ScrollStatus LayerTreeHostImpl::TryScroll(
     const gfx::PointF& screen_space_point,
     InputHandler::ScrollInputType type,
     const ScrollTree& scroll_tree,
     ScrollNode* scroll_node) const {
   InputHandler::ScrollStatus scroll_status;
   scroll_status.main_thread_scrolling_reasons =
       MainThreadScrollingReason::kNotScrollingOnMain;
   if (!!scroll_node->main_thread_scrolling_reasons) {
     TRACE_EVENT0("cc", "LayerImpl::TryScroll: Failed ShouldScrollOnMainThread");
@@ skipping 1745 matching lines @@
 }
 
 void LayerTreeHostImpl::UpdateScrollSourceInfo(bool is_wheel_scroll) {
   if (is_wheel_scroll)
     has_scrolled_by_wheel_ = true;
   else
     has_scrolled_by_touch_ = true;
 }
 
 }  // namespace cc