Make GPU back-pressure work with remote CALayers

content/common/gpu/image_transport_surface_mac.mm

 // 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/common/gpu/image_transport_surface_fbo_mac.h"
 
 #include "content/common/gpu/gpu_messages.h"
-#include "content/common/gpu/image_transport_surface_iosurface_mac.h"
-#include "content/common/gpu/image_transport_surface_calayer_mac.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface_osmesa.h"
 
 namespace content {
 namespace {
 
 // A subclass of GLSurfaceOSMesa that doesn't print an error message when
 // SwapBuffers() is called.
@@ skipping 22 matching lines @@
 scoped_refptr<gfx::GLSurface> ImageTransportSurface::CreateNativeSurface(
     GpuChannelManager* manager,
     GpuCommandBufferStub* stub,
     const gfx::GLSurfaceHandle& surface_handle) {
   DCHECK(surface_handle.transport_type == gfx::NATIVE_DIRECT ||
          surface_handle.transport_type == gfx::NATIVE_TRANSPORT);
 
   switch (gfx::GetGLImplementation()) {
     case gfx::kGLImplementationDesktopGL:
     case gfx::kGLImplementationAppleGL:
-      // TODO(ccameron): If the remote layer API is supported on this system,
-      // use a CALayerStorageProvider instead of an IOSurfaceStorageProvider.
       return scoped_refptr<gfx::GLSurface>(new ImageTransportSurfaceFBO(
-          new IOSurfaceStorageProvider, manager, stub, surface_handle.handle));
+          manager, stub, surface_handle.handle));
     default:
       // Content shell in DRT mode spins up a gpu process which needs an
       // image transport surface, but that surface isn't used to read pixel
       // baselines. So this is mostly a dummy surface.
       if (!g_allow_os_mesa) {
         NOTREACHED();
         return scoped_refptr<gfx::GLSurface>();
       }
       scoped_refptr<gfx::GLSurface> surface(new DRTSurfaceOSMesa());
       if (!surface.get() || !surface->Initialize())
         return surface;
       return scoped_refptr<gfx::GLSurface>(new PassThroughImageTransportSurface(
           manager, stub, surface.get()));
   }
 }
 
 // static
 void ImageTransportSurface::SetAllowOSMesaForTesting(bool allow) {
   g_allow_os_mesa = allow;
 }
 
 }  // namespace content