gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/service/common_decoder.h

 // 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.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_COMMON_DECODER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_COMMON_DECODER_H_
 
 #include <map>
 #include <stack>
 #include <string>
@@ skipping 117 matching lines @@
   template <typename T>
   T GetSharedMemoryAs(unsigned int shm_id, unsigned int offset,
                       unsigned int size) {
     return static_cast<T>(GetAddressAndCheckSize(shm_id, offset, size));
   }
 
   // Get the actual shared memory buffer.
   Buffer GetSharedMemoryBuffer(unsigned int shm_id);
 
  protected:
+  virtual void OnSetAsyncToken(uint32 async_token) {
+    // This should only happen when this function is overriden.
+    NOTREACHED();
+  }
+
   // Executes a common command.
   // Parameters:
   //    command: the command index.
   //    arg_count: the number of CommandBufferEntry arguments.
   //    cmd_data: the command data.
   // Returns:
   //   error::kNoError if no error was found, one of
   //   error::Error otherwise.
   error::Error DoCommonCommand(
       unsigned int command,
@@ skipping 18 matching lines @@
   CommandBufferEngine* engine_;
 
   typedef std::map<uint32, linked_ptr<Bucket> > BucketMap;
   BucketMap buckets_;
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_COMMON_DECODER_H_