Mac: Clean up plumbing of accelerated widgets

gpu/ipc/service/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 "gpu/ipc/service/image_transport_surface.h"
 
 #include "base/macros.h"
+#include "gpu/ipc/service/image_transport_surface_overlay_mac.h"
 #include "gpu/ipc/service/pass_through_image_transport_surface.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_surface_osmesa.h"
 #include "ui/gl/gl_surface_stub.h"
 
 namespace gpu {
 
-scoped_refptr<gl::GLSurface> ImageTransportSurfaceCreateNativeSurface(
-    GpuChannelManager* manager,
-    GpuCommandBufferStub* stub,
-    SurfaceHandle handle);
-
 namespace {
 
 // A subclass of GLSurfaceOSMesa that doesn't print an error message when
 // SwapBuffers() is called.
 class DRTSurfaceOSMesa : public gl::GLSurfaceOSMesa {
  public:
   // Size doesn't matter, the surface is resized to the right size later.
   DRTSurfaceOSMesa()
       : GLSurfaceOSMesa(gl::GLSurface::SURFACE_OSMESA_RGBA, gfx::Size(1, 1)) {}
 
@@ skipping 18 matching lines @@
     GpuChannelManager* manager,
     GpuCommandBufferStub* stub,
     SurfaceHandle surface_handle,
     gl::GLSurface::Format format) {
   DCHECK_NE(surface_handle, kNullSurfaceHandle);
 
   switch (gl::GetGLImplementation()) {
     case gl::kGLImplementationDesktopGL:
     case gl::kGLImplementationDesktopGLCoreProfile:
     case gl::kGLImplementationAppleGL:
-      return ImageTransportSurfaceCreateNativeSurface(manager, stub,
-                                                      surface_handle);
+      return new ImageTransportSurfaceOverlayMac(stub);
     case gl::kGLImplementationMockGL:
       return new gl::GLSurfaceStub;
     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 nullptr;
       }
       scoped_refptr<gl::GLSurface> surface(new DRTSurfaceOSMesa());
       if (!surface.get() || !surface->Initialize(format))
         return surface;
       return scoped_refptr<gl::GLSurface>(
           new PassThroughImageTransportSurface(manager, stub, surface.get()));
   }
 }
 
 // static
 void ImageTransportSurface::SetAllowOSMesaForTesting(bool allow) {
   g_allow_os_mesa = allow;
 }
 
 }  // namespace gpu