DirectCompositorFrameSink Uses CompositorFrameSinkSupport

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 2ee46f4f425a642b7e6f5a7263b594481261f35d..23b5d43f1dc1c89f25ac343389cf86f9f412dcd1 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1489,8 +1489,8 @@ void RenderWidgetHostViewAndroid::StartObservingRootWindow() {
   ui::WindowAndroidCompositor* compositor =
       view_.GetWindowAndroid()->GetCompositor();
   if (compositor) {
-    delegated_frame_host_->RegisterFrameSinkHierarchy(
-        compositor->GetFrameSinkId());
+    static_cast<CompositorImpl*>(compositor)

[boliu, 2017/01/27 23:17:59]

nit: cast in the assignment line

also, what's the argument for this going through the browser compositor? (not
that it's wrong or anything)

[Alex Z., 2017/01/29 14:58:51]

Done.

In the case for desktop chrome, there's a mojo message pipe between the browser
process and gpu process. Mojo would automatically queue messages like 
AddChileFrameSink() until a CompositorFrameSink is attached.

We decided to manage manually the queue here so that it'll be easier to unify
all CompositorFrameSinks later on.

[boliu, 2017/01/30 17:20:22]

That doesn't actually answer my question

Is the answer that desktop also goes through browser compositor as well, and
this is just matching desktop?

[boliu, 2017/01/30 21:13:51]

this is still unanswered?

[Fady Samuel, 2017/01/30 21:45:52]

We cannot currently register a BeginFrame hierarchy until the parent has created
a CompositorFrameSink. The parent knows when it has created a
CompositorFrameSink so setting up registration there seems to make sense.

This simplifies display compositor restart, because we can easily call
AddChildFrameSinks whenever until the parent creates a CompositorFrameSink.

+        ->AddChildFrameSink(delegated_frame_host_->GetFrameSinkId());
   }
 }