Add begin frame paused to android

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 <utility>
 
@@ skipping 1413 matching lines @@
 void RenderWidgetHostViewAndroid::StartObservingRootWindow() {
   DCHECK(content_view_core_);
   // TODO(yusufo): This will need to have a better fallback for cases where
   // setContentViewCore is called with a valid ContentViewCore without a window.
   DCHECK(content_view_core_->GetWindowAndroid());
   DCHECK(is_showing_);
   if (observing_root_window_)
     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.
   uint32_t outstanding_vsync_requests = outstanding_vsync_requests_;
   outstanding_vsync_requests_ = 0;
   RequestVSyncUpdate(outstanding_vsync_requests);
 }
 
 void RenderWidgetHostViewAndroid::StopObservingRootWindow() {
   if (!content_view_core_ || !(content_view_core_->GetWindowAndroid())) {
     DCHECK(!observing_root_window_);
     return;
   }
 
   if (!observing_root_window_)
     return;
 
   // Reset window state variables to their defaults.
   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);
 }
 
 void RenderWidgetHostViewAndroid::SendBeginFrame(base::TimeTicks frame_time,
                                                  base::TimeDelta vsync_period) {
   TRACE_EVENT1("cc", "RenderWidgetHostViewAndroid::SendBeginFrame",
                "frame_time_us", frame_time.ToInternalValue());
 
   if (using_browser_compositor_) {
     // TODO(brianderson): Replace this hardcoded deadline after Android
@@ skipping 554 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