[exo]CompositorFrameSinkHolder calls WillDraw in DidReceiveCompositorFrameAck

components/exo/compositor_frame_sink_holder.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/exo/compositor_frame_sink_holder.h"
 
 #include "cc/resources/returned_resource.h"
 #include "components/exo/surface.h"
 
 namespace exo {
@@ skipping 23 matching lines @@
     cc::ResourceId id,
     const cc::ReleaseCallback& callback) {
   DCHECK(!callback.is_null());
   release_callbacks_[id] = callback;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // cc::mojom::MojoCompositorFrameSinkClient overrides:
 
 void CompositorFrameSinkHolder::DidReceiveCompositorFrameAck() {
-  // TODO(staraz): Implement this
+  if (surface_)
+    surface_->DidReceiveCompositorFrameAck();
 }
 
 void CompositorFrameSinkHolder::OnBeginFrame(const cc::BeginFrameArgs& args) {
   begin_frame_source_->OnBeginFrame(args);
 }
 
 void CompositorFrameSinkHolder::ReclaimResources(
     const cc::ReturnedResourceArray& resources) {
   for (auto& resource : resources) {
     auto it = release_callbacks_.find(resource.id);
     DCHECK(it != release_callbacks_.end());
     if (it != release_callbacks_.end()) {
       it->second.Run(resource.sync_token, resource.lost);
       release_callbacks_.erase(it);
     }
   }
 }
 
 void CompositorFrameSinkHolder::WillDrawSurface(
     const cc::LocalSurfaceId& local_surface_id,
-    const gfx::Rect& damage_rect) {
-  if (surface_)
-    surface_->WillDraw();
-}
+    const gfx::Rect& damage_rect) {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // cc::ExternalBeginFrameSourceClient overrides:
 
 void CompositorFrameSinkHolder::OnNeedsBeginFrames(bool needs_begin_frames) {
   frame_sink_->SetNeedsBeginFrame(needs_begin_frames);
 }
 
 void CompositorFrameSinkHolder::OnDidFinishFrame(const cc::BeginFrameAck& ack) {
   // If there was damage, the submitted CompositorFrame includes the ack.
@@ skipping 11 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // ExoComopositorFrameSink, private:
 
 CompositorFrameSinkHolder::~CompositorFrameSinkHolder() {
   if (surface_)
     surface_->RemoveSurfaceObserver(this);
 }
 
 }  // namespace exo