Make CommandBuffer::Flush asynchronous, and add CommandBuffer::FlushSync with former semantics.

chrome/renderer/command_buffer_proxy.cc

 // Copyright (c) 2009 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 "base/logging.h"
 #include "base/process_util.h"
 #include "base/shared_memory.h"
 #include "base/task.h"
 #include "chrome/common/gpu_messages.h"
 #include "chrome/common/plugin_messages.h"
@@ skipping 76 matching lines @@
 }
 
 gpu::CommandBuffer::State CommandBufferProxy::GetState() {
   // Send will flag state with lost context if IPC fails.
   if (last_state_.error == gpu::error::kNoError)
     Send(new GpuCommandBufferMsg_GetState(route_id_, &last_state_));
 
   return last_state_;
 }
 
-gpu::CommandBuffer::State CommandBufferProxy::Flush(int32 put_offset) {
+void CommandBufferProxy::Flush(int32 put_offset) {
+  AsyncFlush(put_offset, NULL);
+}
+
+gpu::CommandBuffer::State CommandBufferProxy::FlushSync(int32 put_offset) {
   // Send will flag state with lost context if IPC fails.
   if (last_state_.error == gpu::error::kNoError) {
     Send(new GpuCommandBufferMsg_Flush(route_id_,
                                        put_offset,
                                        &last_state_));
   }
 
   return last_state_;
 }
 
@@ skipping 194 matching lines @@
   pending_async_flush_tasks_.pop();
 
   if (task.get()) {
     // Although we need need to update last_state_ while potentially waiting
     // for a synchronous flush to complete, we do not need to invoke the
     // callback synchonously. Also, post it as a non nestable task so it is
     // always invoked by the outermost message loop.
     MessageLoop::current()->PostNonNestableTask(FROM_HERE, task.release());
   }
 }