Revamp OffscreenCanvas commit flow

content/browser/renderer_host/offscreen_canvas_surface_manager.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 "base/lazy_instance.h"
 #include "cc/surfaces/surface_manager.h"
 #include "content/browser/compositor/surface_utils.h"
 #include "content/browser/renderer_host/offscreen_canvas_surface_manager.h"
 
 namespace content {
 
 namespace {
 base::LazyInstance<OffscreenCanvasSurfaceManager>::Leaky g_manager =
     LAZY_INSTANCE_INITIALIZER;
 }
 
 OffscreenCanvasSurfaceManager::OffscreenCanvasSurfaceManager() {
   GetSurfaceManager()->AddObserver(this);
 }
 
 OffscreenCanvasSurfaceManager::~OffscreenCanvasSurfaceManager() {
   registered_surface_instances_.clear();
   GetSurfaceManager()->RemoveObserver(this);
 }
 
 OffscreenCanvasSurfaceManager* OffscreenCanvasSurfaceManager::GetInstance() {
   return g_manager.Pointer();
 }
 
+void OffscreenCanvasSurfaceManager::OnSurfaceCreated(
+    const cc::SurfaceId& surface_id,
+    const gfx::Size& frame_size,
+    float device_scale_factor) {
+  auto surface_iter =
+      registered_surface_instances_.find(surface_id.frame_sink_id());
+  if (surface_iter == registered_surface_instances_.end()) {

[Fady Samuel, 2016/12/15 19:54:52]

no need for braces.

[xlai (Olivia), 2016/12/15 22:20:12]

Done.

+    return;
+  }
+  OffscreenCanvasSurfaceImpl* surfaceImpl = surface_iter->second;
+  surfaceImpl->OnSurfaceCreated(surface_id, frame_size, device_scale_factor);
+}
+
 void OffscreenCanvasSurfaceManager::RegisterOffscreenCanvasSurfaceInstance(
     cc::FrameSinkId frame_sink_id,
     OffscreenCanvasSurfaceImpl* surface_instance) {
   DCHECK(surface_instance);
   DCHECK_EQ(registered_surface_instances_.count(frame_sink_id), 0u);
   registered_surface_instances_[frame_sink_id] = surface_instance;
 }
 
 void OffscreenCanvasSurfaceManager::UnregisterOffscreenCanvasSurfaceInstance(
     cc::FrameSinkId frame_sink_id) {
   DCHECK_EQ(registered_surface_instances_.count(frame_sink_id), 1u);
   registered_surface_instances_.erase(frame_sink_id);
 }
 
 OffscreenCanvasSurfaceImpl* OffscreenCanvasSurfaceManager::GetSurfaceInstance(
     cc::FrameSinkId frame_sink_id) {
   auto search = registered_surface_instances_.find(frame_sink_id);
   if (search != registered_surface_instances_.end()) {
     return search->second;
   }
   return nullptr;
 }
 
 }  // namespace content