Android WebView: flush input events during onVSync

content/browser/renderer_host/render_widget_host_view_android.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_android.h"
 
 #include <android/bitmap.h>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 793 matching lines @@
 void RenderWidgetHostViewAndroid::ShowDisambiguationPopup(
     const gfx::Rect& target_rect, const SkBitmap& zoomed_bitmap) {
   if (!content_view_core_)
     return;
 
   content_view_core_->ShowDisambiguationPopup(target_rect, zoomed_bitmap);
 }
 
 scoped_ptr<SyntheticGestureTarget>
 RenderWidgetHostViewAndroid::CreateSyntheticGestureTarget() {
+  DCHECK(content_view_core_);
+  if (using_synchronous_compositor_) {

[boliu, 2014/08/20 21:41:53]

&& !observing_root_window_

I think this should be done in OnSetNeedsFlushInput, where you don't even need
the using_synchronous_compositor_ check

[hush (inactive), 2014/08/20 22:07:32]

I used to think doing this in OnSetNeedsFlushInput will cause webview to
register observer unnecessarily.
In fact, OnSetNeedsFlushInput is not called for webview unless the input comes
from synthetic gestures.
So yes. I will move this part to OnSetNeedsFlushInput.
Thanks!

On 2014/08/20 21:41:53, boliu wrote:

+    content_view_core_->GetWindowAndroid()->AddObserver(this);
+    observing_root_window_ = true;
+  }
+
   return scoped_ptr<SyntheticGestureTarget>(new SyntheticGestureTargetAndroid(
       host_, content_view_core_->CreateTouchEventSynthesizer()));
 }
 
 void RenderWidgetHostViewAndroid::SendDelegatedFrameAck(
     uint32 output_surface_id) {
   DCHECK(host_);
   cc::CompositorFrameAck ack;
   if (resource_collection_.get())
     resource_collection_->TakeUnusedResourcesForChildCompositor(&ack.resources);
@@ skipping 698 matching lines @@
                                           base::TimeDelta vsync_period) {
   TRACE_EVENT0("cc", "RenderWidgetHostViewAndroid::OnVSync");
   if (!host_)
     return;
 
   if (flush_input_requested_) {
     flush_input_requested_ = false;
     host_->FlushInput();
   }
 
+  if (using_synchronous_compositor_)
+    return;
+
   TRACE_EVENT0("cc", "RenderWidgetHostViewAndroid::SendBeginFrame");
   base::TimeTicks display_time = frame_time + vsync_period;
 
   // TODO(brianderson): Use adaptive draw-time estimation.
   base::TimeDelta estimated_browser_composite_time =
       base::TimeDelta::FromMicroseconds(
           (1.0f * base::Time::kMicrosecondsPerSecond) / (3.0f * 60));
 
   base::TimeTicks deadline = display_time - estimated_browser_composite_time;
 
@@ skipping 149 matching lines @@
   results->orientationAngle = display.RotationAsDegree();
   results->orientationType =
       RenderWidgetHostViewBase::GetOrientationTypeForMobile(display);
   gfx::DeviceDisplayInfo info;
   results->depth = info.GetBitsPerPixel();
   results->depthPerComponent = info.GetBitsPerComponent();
   results->isMonochrome = (results->depthPerComponent == 0);
 }
 
 } // namespace content