iwyu: Use callback_old.h where appropriate, part 1.

gpu/command_buffer/service/gles2_cmd_decoder.h

 // 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 GLES2Decoder class.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_H_
 
 #include <vector>
 
 #include "base/callback.h"
+#include "base/callback_old.h"
 #include "build/build_config.h"
 #include "gpu/command_buffer/service/common_decoder.h"
 #include "ui/gfx/size.h"
 
 namespace gfx {
 class GLContext;
 }
 
 namespace gpu {
 
@@ skipping 96 matching lines @@
  private:
   bool debug_;
 
   DISALLOW_COPY_AND_ASSIGN(GLES2Decoder);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_H_