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

cc/surfaces/display.h

Index: cc/surfaces/display.h
diff --git a/cc/surfaces/display.h b/cc/surfaces/display.h
index a91ae09938d8d3d30673299793d2a7ce449492a6..238f00c5e9ce4c12eed676712f3ccd5cbf171ba2 100644
--- a/cc/surfaces/display.h
+++ b/cc/surfaces/display.h
@@ -56,7 +56,7 @@ class CC_SURFACES_EXPORT Display : public DisplaySchedulerClient,
           gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
           const RendererSettings& settings,
           const FrameSinkId& frame_sink_id,
-          std::unique_ptr<BeginFrameSource> begin_frame_source,
+          BeginFrameSource* begin_frame_source,
           std::unique_ptr<OutputSurface> output_surface,
           std::unique_ptr<DisplayScheduler> scheduler,
           std::unique_ptr<TextureMailboxDeleter> texture_mailbox_deleter);
@@ -115,9 +115,9 @@ class CC_SURFACES_EXPORT Display : public DisplaySchedulerClient,
   bool swapped_since_resize_ = false;
   bool output_is_secure_ = false;
 
-  // The begin_frame_source_ is often known by the output_surface_ and
-  // the scheduler_.
-  std::unique_ptr<BeginFrameSource> begin_frame_source_;
+  // The begin_frame_source_ is not owned here, and also often known by the
+  // output_surface_ and the scheduler_.
+  BeginFrameSource* begin_frame_source_;
   std::unique_ptr<OutputSurface> output_surface_;
   std::unique_ptr<DisplayScheduler> scheduler_;
   std::unique_ptr<ResourceProvider> resource_provider_;