Rework FlushSync to return early if commands have been processed since the last update

gpu/command_buffer/client/cmd_buffer_helper.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.
 
 // This file contains the implementation of the command buffer helper class.
 
 #include "../client/cmd_buffer_helper.h"
 #include "../common/command_buffer.h"
 #include "gpu/common/gpu_trace_event.h"
 
@@ skipping 31 matching lines @@
   put_ = state.put_offset;
   SynchronizeState(state);
   return true;
 }
 
 CommandBufferHelper::~CommandBufferHelper() {
 }
 
 bool CommandBufferHelper::FlushSync() {
   last_put_sent_ = put_;
-  CommandBuffer::State state = command_buffer_->FlushSync(put_);
+  CommandBuffer::State state = command_buffer_->FlushSync(put_, get_);
   SynchronizeState(state);
   return state.error == error::kNoError;
 }
 
 void CommandBufferHelper::Flush() {
   last_put_sent_ = put_;
   command_buffer_->Flush(put_);
 }
 
 // Calls Flush() and then waits until the buffer is empty. Break early if the
@@ skipping 116 matching lines @@
   SynchronizeState(state);
   return static_cast<error::Error>(state.error);
 }
 
 void CommandBufferHelper::SynchronizeState(CommandBuffer::State state) {
   get_ = state.get_offset;
   last_token_read_ = state.token;
 }
 
 }  // namespace gpu