[Android] Provide synchronized input flush with BeginFrame

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 42e18691d18a1f02194a705d0ba4c9858007c803..fdf669a0baadc5ee8ae471fc1f34638819dff288 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -113,7 +113,8 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
       texture_id_in_layer_(0),
       current_mailbox_output_surface_id_(kUndefinedOutputSurfaceId),
       weak_ptr_factory_(this),
-      overscroll_effect_enabled_(true) {
+      overscroll_effect_enabled_(true),
+      flush_input_requested_(false) {
   if (CompositorImpl::UsesDirectGL()) {
     surface_texture_transport_.reset(new SurfaceTextureTransportClient());
     layer_ = surface_texture_transport_->Initialize();
@@ -455,8 +456,16 @@ void RenderWidgetHostViewAndroid::OnDidChangeBodyBackgroundColor(
 void RenderWidgetHostViewAndroid::SendBeginFrame(
     const cc::BeginFrameArgs& args) {
   TRACE_EVENT0("cc", "RenderWidgetHostViewAndroid::SendBeginFrame");
-  if (host_)
-    host_->Send(new ViewMsg_BeginFrame(host_->GetRoutingID(), args));
+  if (!host_)
+    return;
+
+  if (flush_input_requested_) {
+    flush_input_requested_ = false;
+    host_->FlushInput();
+    RemoveBeginFrameSubscriber();
+  }
+
+  host_->Send(new ViewMsg_BeginFrame(host_->GetRoutingID(), args));
 }
 
 void RenderWidgetHostViewAndroid::OnSetNeedsBeginFrame(
@@ -467,7 +476,10 @@ void RenderWidgetHostViewAndroid::OnSetNeedsBeginFrame(
   // we have to make sure calls to ContentViewCoreImpl's SetNeedsBeginFrame
   // are balanced, even if RenderWidgetHostViewAndroid's may not be.
   if (content_view_core_ && needs_begin_frame_ != enabled) {
-    content_view_core_->SetNeedsBeginFrame(enabled);
+    if (enabled)
+      AddBeginFrameSubscriber();
+    else
+      RemoveBeginFrameSubscriber();
     needs_begin_frame_ = enabled;
   }
 }
@@ -834,6 +846,14 @@ void RenderWidgetHostViewAndroid::RemoveLayers() {
   content_view_core_->RemoveLayer(layer_);
 }
 
+void RenderWidgetHostViewAndroid::AddBeginFrameSubscriber() {
+  content_view_core_->SetNeedsBeginFrame(true);

[brianderson, 2013/09/13 21:49:27]

Can you rename ContentViewCore's SetNeedsBeginFrame to AddBeginFrameSubscriber
as well?

[jdduke (slow), 2013/09/16 15:16:04]

Done.

+}
+
+void RenderWidgetHostViewAndroid::RemoveBeginFrameSubscriber() {
+  content_view_core_->SetNeedsBeginFrame(false);
+}
+
 bool RenderWidgetHostViewAndroid::Animate(base::TimeTicks frame_time) {
   if (!overscroll_effect_)
     return false;
@@ -966,6 +986,13 @@ InputEventAckState RenderWidgetHostViewAndroid::FilterInputEvent(
   return INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
 }
 
+void RenderWidgetHostViewAndroid::OnSetNeedsFlushInput() {
+  if (flush_input_requested_)
+    return;
+  flush_input_requested_ = true;
+  AddBeginFrameSubscriber();
+}
+
 void RenderWidgetHostViewAndroid::OnAccessibilityEvents(
     const std::vector<AccessibilityHostMsg_EventParams>& params) {
   if (!host_ ||