[exo] Clean up BeginFrame distribution & add acks in Surface.

components/exo/compositor_frame_sink_holder.cc

Index: components/exo/compositor_frame_sink_holder.cc
diff --git a/components/exo/compositor_frame_sink_holder.cc b/components/exo/compositor_frame_sink_holder.cc
index 3d55a7d68b1def413ddcd108acc6cb1b6235c2e7..3d6e5a2716e09fa5bfb30535ffe5bfa3984df74c 100644
--- a/components/exo/compositor_frame_sink_holder.cc
+++ b/components/exo/compositor_frame_sink_holder.cc
@@ -22,6 +22,7 @@ CompositorFrameSinkHolder::CompositorFrameSinkHolder(
       begin_frame_source_(base::MakeUnique<cc::ExternalBeginFrameSource>(this)),
       weak_factory_(this) {
   surface_->AddSurfaceObserver(this);
+  surface_->SetBeginFrameSource(begin_frame_source_.get());
 }
 
 bool CompositorFrameSinkHolder::HasReleaseCallbackForResource(
@@ -36,11 +37,6 @@ void CompositorFrameSinkHolder::SetResourceReleaseCallback(
   release_callbacks_[id] = callback;
 }
 
-void CompositorFrameSinkHolder::SetNeedsBeginFrame(bool needs_begin_frame) {
-  needs_begin_frame_ = needs_begin_frame;
-  OnNeedsBeginFrames(needs_begin_frame);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // cc::mojom::MojoCompositorFrameSinkClient overrides:
 
@@ -49,10 +45,6 @@ void CompositorFrameSinkHolder::DidReceiveCompositorFrameAck() {
 }
 
 void CompositorFrameSinkHolder::OnBeginFrame(const cc::BeginFrameArgs& args) {
-  // TODO(eseckler): Hook up |surface_| to the ExternalBeginFrameSource.
-  if (surface_)
-    surface_->BeginFrame(args.frame_time);
-
   begin_frame_source_->OnBeginFrame(args);
 }
 
@@ -73,22 +65,10 @@ void CompositorFrameSinkHolder::WillDrawSurface(
     const gfx::Rect& damage_rect) {
   if (surface_)
     surface_->WillDraw();
-
-  UpdateNeedsBeginFrame();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// cc::BeginFrameObserver overrides:
-
-const cc::BeginFrameArgs& CompositorFrameSinkHolder::LastUsedBeginFrameArgs()
-    const {
-  return last_begin_frame_args_;
 }
 
-void CompositorFrameSinkHolder::OnBeginFrameSourcePausedChanged(bool paused) {}
-
 ////////////////////////////////////////////////////////////////////////////////
-// cc::ExternalBeginFrameSouceClient overrides:
+// cc::ExternalBeginFrameSourceClient overrides:
 
 void CompositorFrameSinkHolder::OnNeedsBeginFrames(bool needs_begin_frames) {
   frame_sink_->SetNeedsBeginFrame(needs_begin_frames);
@@ -114,16 +94,4 @@ CompositorFrameSinkHolder::~CompositorFrameSinkHolder() {
     surface_->RemoveSurfaceObserver(this);
 }
 
-void CompositorFrameSinkHolder::UpdateNeedsBeginFrame() {
-  if (!begin_frame_source_)
-    return;
-
-  bool needs_begin_frame = surface_ && surface_->NeedsBeginFrame();
-  if (needs_begin_frame == needs_begin_frame_)
-    return;
-
-  needs_begin_frame_ = needs_begin_frame;
-  OnNeedsBeginFrames(needs_begin_frame_);
-}
-
 }  // namespace exo