Make OffscreenCanvas animation in sync with its placeholder canvas's parent frame rate

content/browser/renderer_host/offscreen_canvas_surface_impl.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 "content/browser/renderer_host/offscreen_canvas_surface_impl.h"
 
 #include <utility>
 
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_manager.h"
 #include "content/browser/compositor/surface_utils.h"
 #include "content/browser/renderer_host/offscreen_canvas_surface_manager.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 OffscreenCanvasSurfaceImpl::OffscreenCanvasSurfaceImpl(
+    const cc::FrameSinkId& parent_frame_sink_id,
     const cc::FrameSinkId& frame_sink_id,
     blink::mojom::OffscreenCanvasSurfaceClientPtr client)
-    : client_(std::move(client)), frame_sink_id_(frame_sink_id) {
+    : client_(std::move(client)),
+      frame_sink_id_(frame_sink_id),
+      parent_frame_sink_id_(parent_frame_sink_id) {
   OffscreenCanvasSurfaceManager::GetInstance()
       ->RegisterOffscreenCanvasSurfaceInstance(frame_sink_id_, this);
 }
 
 OffscreenCanvasSurfaceImpl::~OffscreenCanvasSurfaceImpl() {
   if (frame_sink_id_.is_valid()) {
     OffscreenCanvasSurfaceManager::GetInstance()
         ->UnregisterOffscreenCanvasSurfaceInstance(frame_sink_id_);
   }
 }
 
 // static
 void OffscreenCanvasSurfaceImpl::Create(
+    const cc::FrameSinkId& parent_frame_sink_id,
     const cc::FrameSinkId& frame_sink_id,
     blink::mojom::OffscreenCanvasSurfaceClientPtr client,
     blink::mojom::OffscreenCanvasSurfaceRequest request) {
   std::unique_ptr<OffscreenCanvasSurfaceImpl> impl =
-      base::MakeUnique<OffscreenCanvasSurfaceImpl>(frame_sink_id,
-                                                   std::move(client));
+      base::MakeUnique<OffscreenCanvasSurfaceImpl>(
+          parent_frame_sink_id, frame_sink_id, std::move(client));
   OffscreenCanvasSurfaceImpl* surface_service = impl.get();
   surface_service->binding_ =
       mojo::MakeStrongBinding(std::move(impl), std::move(request));
 }
 
 void OffscreenCanvasSurfaceImpl::OnSurfaceCreated(
     const cc::SurfaceInfo& surface_info) {
   DCHECK_EQ(surface_info.id().frame_sink_id(), frame_sink_id_);
   if (!current_local_frame_id_.is_valid() ||
       surface_info.id().local_frame_id() != current_local_frame_id_) {
     current_local_frame_id_ = surface_info.id().local_frame_id();
     if (client_)
       client_->OnSurfaceCreated(surface_info);
   }
 }
 
 void OffscreenCanvasSurfaceImpl::Require(const cc::SurfaceId& surface_id,
                                          const cc::SurfaceSequence& sequence) {
   GetSurfaceManager()->RequireSequence(surface_id, sequence);
 }
 
 void OffscreenCanvasSurfaceImpl::Satisfy(const cc::SurfaceSequence& sequence) {
   GetSurfaceManager()->SatisfySequence(sequence);
 }
 
 }  // namespace content