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

gpu/command_buffer/client/ring_buffer_test.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 tests for the RingBuffer class.
 
 #include "gpu/command_buffer/client/ring_buffer.h"
 #include "base/callback.h"
 #include "base/message_loop.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
@@ skipping 37 matching lines @@
     parser_ = new CommandParser(ring_buffer.ptr,
                                 ring_buffer.size,
                                 0,
                                 ring_buffer.size,
                                 0,
                                 api_mock_.get());
 
     gpu_scheduler_.reset(new GpuScheduler(
         command_buffer_.get(), NULL, parser_, INT_MAX));
     command_buffer_->SetPutOffsetChangeCallback(NewCallback(
-        gpu_scheduler_.get(), &GpuScheduler::ProcessCommands));
+        gpu_scheduler_.get(), &GpuScheduler::PutChanged));
 
     api_mock_->set_engine(gpu_scheduler_.get());
 
     helper_.reset(new CommandBufferHelper(command_buffer_.get()));
     helper_->Initialize(kBufferSize);
   }
 
   int32 GetToken() {
     return command_buffer_->GetState().token;
   }
@@ skipping 183 matching lines @@
   void* pointer1 = allocator_->Alloc(kSize);
   EXPECT_EQ(buffer_start_, static_cast<int8*>(pointer1));
 
   // Check that the token has indeed passed.
   EXPECT_LE(tokens[0], GetToken());
 
   allocator_->FreePendingToken(pointer1, helper_->InsertToken());
 }
 
 }  // namespace gpu