Add begin frame paused to android

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 2c0dafc7ca7e8ec9965e34ad0037d1bb11c193ce..175ee37477ec07463fd82f81c4b2c5c8110f65d6 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1431,6 +1431,8 @@ void RenderWidgetHostViewAndroid::StartObservingRootWindow() {
     return;
 
   observing_root_window_ = true;
+  if (host_)
+    host_->Send(new ViewMsg_SetBeginFramePaused(host_->GetRoutingID(), false));
   content_view_core_->GetWindowAndroid()->AddObserver(this);
 
   // Clear existing vsync requests to allow a request to the new window.
@@ -1452,6 +1454,8 @@ void RenderWidgetHostViewAndroid::StopObservingRootWindow() {
   is_window_activity_started_ = true;
   is_window_visible_ = true;
   observing_root_window_ = false;
+  if (host_)
+    host_->Send(new ViewMsg_SetBeginFramePaused(host_->GetRoutingID(), true));

[enne (OOO), 2016/05/16 17:22:30]

Does StopObservingRootWindow (and this set begin frame paused) happen during
destruction? Just curious about shutdown-related deadlock if the browser goes
away first.

[boliu, 2016/05/16 17:27:01]

Good question. Looks yes:

~RenderWidgetHostViewAndroid -> SetContentViewCore(NULL) -> calls
StopObservingRootWindow and skips StartObservingRootWindow

   content_view_core_->GetWindowAndroid()->RemoveObserver(this);
 }