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

ppapi/shared_impl/ppb_video_decoder_shared.cc

Index: ppapi/shared_impl/ppb_video_decoder_shared.cc
diff --git a/ppapi/shared_impl/ppb_video_decoder_shared.cc b/ppapi/shared_impl/ppb_video_decoder_shared.cc
index 7d8d021b5b398156252ac8ac5e121aa58acf78f2..5232e6c3b30b2cd5c7cbeb8c1a1310464f26ba76 100644
--- a/ppapi/shared_impl/ppb_video_decoder_shared.cc
+++ b/ppapi/shared_impl/ppb_video_decoder_shared.cc
@@ -96,16 +96,8 @@ void PPB_VideoDecoder_Shared::RunBitstreamBufferCallback(
 }
 
 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