Mus+Ash: Use standard cc mechanism for surface lifetime.

services/ui/ws/server_window_surface.h

Index: services/ui/ws/server_window_surface.h
diff --git a/services/ui/ws/server_window_surface.h b/services/ui/ws/server_window_surface.h
index a4514dd4a6e5930d83345fe218c88d65a9b6f95e..2f09b62823edb79512e182630d3ee1eed84ecf15 100644
--- a/services/ui/ws/server_window_surface.h
+++ b/services/ui/ws/server_window_surface.h
@@ -50,15 +50,16 @@ class ServerWindowSurface : public mojom::Surface,
       cc::CompositorFrame frame,
       const SubmitCompositorFrameCallback& callback) override;
 
+  const cc::FrameSinkId& frame_sink_id() const { return frame_sink_id_; }

[rjkroege, 2016/10/07 19:34:50]

would be awesome to remind people what a FrameSinkId is.

[Fady Samuel, 2016/10/07 20:31:33]

Done.

   const cc::LocalFrameId& local_frame_id() const { return local_frame_id_; }
 
+  bool has_frame() const { return !local_frame_id_.is_null(); }
+
   cc::SurfaceId GetSurfaceId() const;
 
-  // Destroys old surfaces that have been outdated by a new surface.
-  void DestroySurfacesScheduledForDestruction();
+  ServerWindow* window();

[rjkroege, 2016/10/07 19:34:50]

if I remember correctly, we need windows that don't have surfaces. How does that
affect this code?

[Fady Samuel, 2016/10/07 20:31:33]

A surface has a window but a window may not have a surface. This is the
relationship here.

[rjkroege, 2016/10/07 20:48:13]

was an off-topic comment. sorry

[Fady Samuel, 2016/10/07 21:04:33]

Acknowledged.

 
  private:
-  ServerWindow* window();
 
   // SurfaceFactoryClient implementation.
   void ReturnResources(const cc::ReturnedResourceArray& resources) override;
@@ -77,9 +78,6 @@ class ServerWindowSurface : public mojom::Surface,
   mojom::SurfaceClientPtr client_;
   mojo::Binding<Surface> binding_;
 
-  // Set of surface ids that need to be destroyed.
-  std::set<cc::LocalFrameId> surfaces_scheduled_for_destruction_;
-
   bool may_contain_video_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ServerWindowSurface);