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

services/ui/surfaces/display_compositor.h

Index: services/ui/surfaces/display_compositor.h
diff --git a/services/ui/surfaces/display_compositor.h b/services/ui/surfaces/display_compositor.h
index 97c89f7379cece91f22b53cdbecc5bd2b0aee223..1233609364270f91920af2e7fe93a77ab0f54f5b 100644
--- a/services/ui/surfaces/display_compositor.h
+++ b/services/ui/surfaces/display_compositor.h
@@ -33,6 +33,7 @@ class ImageFactory;
 namespace cc {
 class Display;
 class SurfaceManager;
+class SyntheticBeginFrameSource;
 }
 
 namespace ui {
@@ -97,7 +98,8 @@ class DisplayCompositor : public cc::SurfaceObserver,
 
   std::unique_ptr<cc::Display> CreateDisplay(
       const cc::FrameSinkId& frame_sink_id,
-      gpu::SurfaceHandle surface_handle);
+      gpu::SurfaceHandle surface_handle,
+      cc::SyntheticBeginFrameSource* begin_frame_source);
 
   const cc::SurfaceId& GetRootSurfaceId() const;