Plumb thru that we cache the front buffer.

content/common/gpu/image_transport_surface_win.cc

 // Copyright (c) 2011 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.
 
 #if defined(ENABLE_GPU)
 
 #include "content/common/gpu/image_transport_surface.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 14 matching lines @@
 class PbufferImageTransportSurface
     : public gfx::GLSurfaceAdapter,
       public ImageTransportSurface,
       public base::SupportsWeakPtr<PbufferImageTransportSurface> {
  public:
   PbufferImageTransportSurface(GpuChannelManager* manager,
                                int32 render_view_id,
                                int32 renderer_id,
                                int32 command_buffer_id);
 
-  // GLSurface implementation
-  virtual bool Initialize();
-  virtual void Destroy();
-  virtual bool IsOffscreen();
-  virtual bool SwapBuffers();
+  // gfx::GLSurface implementation
+  virtual bool Initialize() OVERRIDE;
+  virtual void Destroy() OVERRIDE;
+  virtual bool IsOffscreen() OVERRIDE;
+  virtual bool SwapBuffers() OVERRIDE;
+  virtual bool PostSubBuffer(int x, int y, int width, int height) OVERRIDE;
+  virtual std::string GetExtensions() OVERRIDE;
 
  protected:
   // ImageTransportSurface implementation
   virtual void OnNewSurfaceACK(uint64 surface_id,
                                TransportDIB::Handle shm_handle) OVERRIDE;
   virtual void OnBuffersSwappedACK() OVERRIDE;
   virtual void OnPostSubBufferACK() OVERRIDE;
   virtual void OnResizeViewACK() OVERRIDE;
   virtual void OnResize(gfx::Size size) OVERRIDE;
 
@@ skipping 52 matching lines @@
   if (!surface_handle)
     return false;
 
   helper_->DeferToFence(base::Bind(
       &PbufferImageTransportSurface::SendBuffersSwapped,
       AsWeakPtr()));
 
   return true;
 }
 
+bool PbufferImageTransportSurface::PostSubBuffer(
+    int x, int y, int width, int height) {
+  NOTREACHED();
+  return false;
+}
+
+std::string PbufferImageTransportSurface::GetExtensions() {
+  std::string extensions = gfx::GLSurface::GetExtensions();
+  extensions += extensions.empty() ? "" : " ";
+  extensions += "GL_CHROMIUM_front_buffer_cached";
+  return extensions;
+}
+
 void PbufferImageTransportSurface::SendBuffersSwapped() {
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.surface_id = reinterpret_cast<int64>(GetShareHandle());
   params.size = GetSize();
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
 
   helper_->SetScheduled(false);
 }
 
 void PbufferImageTransportSurface::OnBuffersSwappedACK() {
@@ skipping 50 matching lines @@
                                                    surface.get());
   }
 
   if (surface->Initialize())
     return surface;
   else
     return NULL;
 }
 
 #endif  // ENABLE_GPU