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

content/renderer/pepper_plugin_delegate_impl.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.
 
 #include "content/renderer/pepper_plugin_delegate_impl.h"
 
 #include <cmath>
 #include <queue>
 
 #include "app/surface/transport_dib.h"
@@ skipping 546 matching lines @@
   // chrome/renderer/webplugin_delegate_proxy.cc, method
   // WebPluginDelegateProxy::CreateBitmap() for similar code). The TransportDIB
   // is cached in the browser, and is freed (in typical cases) by the
   // PlatformImage2DImpl's destructor.
   TransportDIB::Handle dib_handle;
   IPC::Message* msg = new ViewHostMsg_AllocTransportDIB(buffer_size,
                                                         true,
                                                         &dib_handle);
   if (!RenderThread::current()->Send(msg))
     return NULL;
-  if (!TransportDIB::is_valid(dib_handle))
+  if (!TransportDIB::is_valid_handle(dib_handle))
     return NULL;
 
   TransportDIB* dib = TransportDIB::Map(dib_handle);
 #else
   static int next_dib_id = 0;
   TransportDIB* dib = TransportDIB::Create(buffer_size, next_dib_id++);
   if (!dib)
     return NULL;
 #endif
 
@@ skipping 380 matching lines @@
 }
 
 void PepperPluginDelegateImpl::HasUnsupportedFeature() {
   render_view_->Send(new ViewHostMsg_PDFHasUnsupportedFeature(
       render_view_->routing_id()));
 }
 
 P2PSocketDispatcher* PepperPluginDelegateImpl::GetP2PSocketDispatcher() {
   return render_view_->p2p_socket_dispatcher();
 }