Moves ownership of the cc::Display's BeginFrameSource out of Display.

blimp/client/support/compositor/blimp_embedder_compositor.h

Index: blimp/client/support/compositor/blimp_embedder_compositor.h
diff --git a/blimp/client/support/compositor/blimp_embedder_compositor.h b/blimp/client/support/compositor/blimp_embedder_compositor.h
index 050d85907a4a08dee01e4eee85e6688c922b0343..e30b2272fd04b9606c7837158279506b06464cf3 100644
--- a/blimp/client/support/compositor/blimp_embedder_compositor.h
+++ b/blimp/client/support/compositor/blimp_embedder_compositor.h
@@ -16,6 +16,7 @@
 
 namespace cc {
 class AnimationHost;
+class BeginFrameSource;
 class ContextProvider;
 class Display;
 class LayerTreeHost;
@@ -82,6 +83,7 @@ class BlimpEmbedderCompositor : public cc::LayerTreeHostClient,
   scoped_refptr<cc::ContextProvider> context_provider_;
 
   bool compositor_frame_sink_request_pending_;
+  std::unique_ptr<cc::BeginFrameSource> begin_frame_source_;
   std::unique_ptr<cc::Display> display_;
 
   gfx::Size viewport_size_in_px_;