Hook up ui::Compositor to Display's BeginFrameSource

cc/surfaces/surface_display_output_surface.cc

Index: cc/surfaces/surface_display_output_surface.cc
diff --git a/cc/surfaces/surface_display_output_surface.cc b/cc/surfaces/surface_display_output_surface.cc
index dfb491ede62bb7a5c41755c89514d399b93eb950..358f1779dc4f87bf997390a08d031b25a4c722f5 100644
--- a/cc/surfaces/surface_display_output_surface.cc
+++ b/cc/surfaces/surface_display_output_surface.cc
@@ -21,7 +21,7 @@ SurfaceDisplayOutputSurface::SurfaceDisplayOutputSurface(
     scoped_refptr<ContextProvider> worker_context_provider)
     : OutputSurface(std::move(context_provider),
                     std::move(worker_context_provider)),
-      display_client_(NULL),
+      display_client_(nullptr),
       factory_(surface_manager, this),
       allocator_(allocator) {
   factory_.set_needs_sync_points(false);
@@ -41,12 +41,6 @@ SurfaceDisplayOutputSurface::~SurfaceDisplayOutputSurface() {
   }
 }
 
-void SurfaceDisplayOutputSurface::ReceivedVSyncParameters(
-    base::TimeTicks timebase,
-    base::TimeDelta interval) {
-  CommitVSyncParameters(timebase, interval);
-}
-
 void SurfaceDisplayOutputSurface::SwapBuffers(CompositorFrame* frame) {
   gfx::Size frame_size =
       frame->delegated_frame_data->render_pass_list.back()->output_rect.size();
@@ -109,7 +103,8 @@ void SurfaceDisplayOutputSurface::ReturnResources(
 
 void SurfaceDisplayOutputSurface::SetBeginFrameSource(
     BeginFrameSource* begin_frame_source) {
-  // TODO(tansell): Hook this up.
+  DCHECK(client_);
+  client_->SetBeginFrameSource(begin_frame_source);
 }
 
 void SurfaceDisplayOutputSurface::SwapBuffersComplete(SurfaceDrawStatus drawn) {