GPU process clients can perform a "shallow" finish.

gpu/command_buffer/client/gles2_implementation.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.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <algorithm>
 #include <map>
@@ skipping 795 matching lines @@
   // Flush our command buffer
   // (tell the service to execute up to the flush cmd.)
   helper_->CommandBufferHelper::Flush();
 }
 
 void GLES2Implementation::Finish() {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   FinishHelper();
 }
 
+void GLES2Implementation::ShallowFinishCHROMIUM() {
+  GPU_CLIENT_SINGLE_THREAD_CHECK();
+  // Flush our command buffer (tell the service to execute up to the flush cmd
+  // and don't return until it completes).
+  helper_->CommandBufferHelper::Finish();
+}
+
 bool GLES2Implementation::MustBeContextLost() {
   bool context_lost = helper_->IsContextLost();
   if (!context_lost) {
     WaitForCmd();
     context_lost = helper_->IsContextLost();
   }
   GPU_CHECK(context_lost);
   return context_lost;
 }
 
@@ skipping 3018 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu