Adds a TransportDIB::Id value that is explicitly invalid and use it when compositing

content/plugin/webplugin_accelerated_surface_proxy_mac.cc

 // Copyright (c) 2010 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.
 
 #import <OpenGL/OpenGL.h>
 
 #include "content/plugin/webplugin_accelerated_surface_proxy_mac.h"
 
 #include "app/surface/accelerated_surface_mac.h"
 #include "app/surface/transport_dib.h"
@@ skipping 33 matching lines @@
 
 void WebPluginAcceleratedSurfaceProxy::SetSize(const gfx::Size& size) {
   if (!surface_)
     return;
 
   uint64 io_surface_id = surface_->SetSurfaceSize(size);
   if (io_surface_id) {
     plugin_proxy_->SetAcceleratedSurface(window_handle_, size, io_surface_id);
   } else {
     TransportDIB::Handle transport_dib = surface_->SetTransportDIBSize(size);
-    if (TransportDIB::is_valid(transport_dib)) {
+    if (TransportDIB::is_valid_handle(transport_dib)) {
       plugin_proxy_->SetAcceleratedDIB(window_handle_, size, transport_dib);
     }
   }
 }
 
 CGLContextObj WebPluginAcceleratedSurfaceProxy::context() {
   return surface_ ? surface_->context() : NULL;
 }
 
 void WebPluginAcceleratedSurfaceProxy::StartDrawing() {
   if (!surface_)
     return;
 
   surface_->MakeCurrent();
   surface_->Clear(gfx::Rect(surface_->GetSize()));
 }
 
 void WebPluginAcceleratedSurfaceProxy::EndDrawing() {
   if (!surface_)
     return;
 
   surface_->SwapBuffers();
   plugin_proxy_->AcceleratedFrameBuffersDidSwap(
       window_handle_, surface_->GetSurfaceId());
 }