Plumb thru that we cache the front buffer.

content/common/gpu/image_transport_surface_mac.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/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 71 matching lines @@
                                     int32 render_view_id,
                                     int32 renderer_id,
                                     int32 command_buffer_id,
                                     gfx::PluginWindowHandle handle);
 
   // 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;
   virtual gfx::Size GetSize() OVERRIDE;
   virtual bool OnMakeCurrent(gfx::GLContext* context) OVERRIDE;
   virtual unsigned int GetBackingFrameBufferObject() OVERRIDE;
 
  protected:
   // ImageTransportSurface implementation
   virtual void OnBuffersSwappedACK() OVERRIDE;
   virtual void OnPostSubBufferACK() OVERRIDE;
   virtual void OnNewSurfaceACK(uint64 surface_id,
@@ skipping 129 matching lines @@
   return true;
 }
 
 bool IOSurfaceImageTransportSurface::PostSubBuffer(
     int x, int y, int width, int height) {
   NOTREACHED();
   return false;
 }
 
 std::string IOSurfaceImageTransportSurface::GetExtensions() {
-  return gfx::GLSurface::GetExtensions();
+  std::string extensions = gfx::GLSurface::GetExtensions();
+  extensions += extensions.empty() ? "" : " ";
+  extensions += "GL_CHROMIUM_front_buffer_cached";
+  return extensions;
 }
 
 gfx::Size IOSurfaceImageTransportSurface::GetSize() {
   return size_;
 }
 
 void IOSurfaceImageTransportSurface::OnBuffersSwappedACK() {
   helper_->SetScheduled(true);
 }
 
@@ skipping 192 matching lines @@
   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, previous_fbo_id);
 
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.surface_id = next_id_;
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
 
   helper_->SetScheduled(false);
   return true;
 }
 
+bool TransportDIBImageTransportSurface::PostSubBuffer(
+    int x, int y, int width, int height) {
+  NOTREACHED();
+  return false;
+}
+
 std::string TransportDIBImageTransportSurface::GetExtensions() {
-  return gfx::GLSurface::GetExtensions();
+  std::string extensions = gfx::GLSurface::GetExtensions();
+  extensions += extensions.empty() ? "" : " ";
+  extensions += "GL_CHROMIUM_front_buffer_cached";
+  return extensions;
 }
 
 gfx::Size TransportDIBImageTransportSurface::GetSize() {
   return size_;
 }
 
 void TransportDIBImageTransportSurface::OnBuffersSwappedACK() {
   helper_->SetScheduled(true);
 }
 
@@ skipping 82 matching lines @@
       NOTREACHED();
       return NULL;
   }
   if (surface->Initialize())
     return surface;
   else
     return NULL;
 }
 
 #endif  // defined(USE_GPU)