PPAPI: Make GLES2 calls resilient to bad/dead resources.

ppapi/shared_impl/ppb_video_decoder_shared.cc

 // Copyright (c) 2012 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 "ppapi/shared_impl/ppb_video_decoder_shared.h"
 
 #include "base/logging.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/shared_impl/ppb_graphics_3d_shared.h"
@@ skipping 78 matching lines @@
     int32 bitstream_buffer_id, int32 result) {
   CallbackById::iterator it =
       bitstream_buffer_callbacks_.find(bitstream_buffer_id);
   DCHECK(it != bitstream_buffer_callbacks_.end());
   scoped_refptr<TrackedCallback> cc = it->second;
   bitstream_buffer_callbacks_.erase(it);
   cc->Run(PP_OK);
 }
 
 void PPB_VideoDecoder_Shared::FlushCommandBuffer() {
-  if (gles2_impl_) {
-    // To call Flush() we have to tell Graphics3D that we hold the proxy lock.
-    thunk::EnterResource<thunk::PPB_Graphics3D_API, false> enter_g3d(
-        graphics_context_, false);
-    DCHECK(enter_g3d.succeeded());
-    PPB_Graphics3D_Shared* graphics3d =
-        static_cast<PPB_Graphics3D_Shared*>(enter_g3d.object());
-    PPB_Graphics3D_Shared::ScopedNoLocking dont_lock(graphics3d);
+  if (gles2_impl_)
     gles2_impl_->Flush();
-  }
 }
 
 }  // namespace ppapi