Android: Throttle BeginFrame messages sent from the browser.

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 739dd3f676ede9b8b9199822e9280e22c3a15050..6e96ce21fda1381557101dc0ff64cbeed471557d 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -81,7 +81,8 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
       ime_adapter_android_(this),
       cached_background_color_(SK_ColorWHITE),
       texture_id_in_layer_(0),
-      weak_ptr_factory_(this) {
+      weak_ptr_factory_(this),
+      begin_frame_pending_(false) {
   if (CompositorImpl::UsesDirectGL()) {
     surface_texture_transport_.reset(new SurfaceTextureTransportClient());
     layer_ = surface_texture_transport_->Initialize();
@@ -409,9 +410,19 @@ void RenderWidgetHostViewAndroid::OnDidChangeBodyBackgroundColor(
 
 void RenderWidgetHostViewAndroid::SendBeginFrame(
     base::TimeTicks frame_time) {
-  if (host_)
+  // Throttle the renderer if we are behind. Also only send another beginFrame
+  // if we received a frame for the last beginFrame.
+  if (!ack_callbacks_.empty() || begin_frame_pending_) {
+    if (content_view_core_)
+      content_view_core_->SetVSyncNotificationEnabled(true);
+    return;
+  }
+
+  if (host_) {
+    begin_frame_pending_ = true;
     host_->Send(new ViewMsg_BeginFrame(host_->GetRoutingID(),
                                        frame_time));
+  }
 }
 
 void RenderWidgetHostViewAndroid::OnSetNeedsBeginFrame(
@@ -592,6 +603,7 @@ void RenderWidgetHostViewAndroid::ComputeContentsSize(
 
 void RenderWidgetHostViewAndroid::OnSwapCompositorFrame(
     scoped_ptr<cc::CompositorFrame> frame) {
+  begin_frame_pending_ = false;
   // Always let ContentViewCore know about the new frame first, so it can decide
   // to schedule a Draw immediately when it sees the texture layer invalidation.
   if (content_view_core_) {