Mac ÜC: Enable back-pressure for the browser compositor

content/browser/compositor/gpu_process_transport_factory.cc

 // Copyright 2014 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/compositor/gpu_process_transport_factory.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 307 matching lines @@
 void GpuProcessTransportFactory::AddObserver(
     ImageTransportFactoryObserver* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void GpuProcessTransportFactory::RemoveObserver(
     ImageTransportFactoryObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
+#if defined(OS_MACOSX)
+void GpuProcessTransportFactory::OnSurfaceDisplayed(int surface_id) {
+  BrowserCompositorOutputSurface* surface = output_surface_map_.Lookup(
+      surface_id);
+  if (surface)
+    surface->OnSurfaceDisplayed();
+}
+#endif
+
 scoped_refptr<cc::ContextProvider>
 GpuProcessTransportFactory::SharedMainThreadContextProvider() {
   if (shared_main_thread_contexts_.get())
     return shared_main_thread_contexts_;
 
   // In threaded compositing mode, we have to create our own context for the
   // main thread since the compositor's context will be bound to the
   // compositor thread. When not in threaded mode, we still need a separate
   // context so that skia and gl_helper don't step on each other.
   shared_main_thread_contexts_ = ContextProviderCommandBuffer::Create(
@@ skipping 85 matching lines @@
   FOR_EACH_OBSERVER(ImageTransportFactoryObserver,
                     observer_list_,
                     OnLostResources());
 
   // Kill things that use the shared context before killing the shared context.
   lost_gl_helper.reset();
   lost_shared_main_thread_contexts  = NULL;
 }
 
 }  // namespace content