Remove unused fields from //content.

content/browser/renderer_host/delegated_frame_host.h

 // Copyright 2014 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 CONTENT_BROWSER_RENDERER_HOST_DELEGATED_FRAME_HOST_H_
 #define CONTENT_BROWSER_RENDERER_HOST_DELEGATED_FRAME_HOST_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 299 matching lines @@
 
   // Callback used to pass the output request to the layer or to a function
   // specified by a test.
   base::Callback<void(std::unique_ptr<cc::CopyOutputRequest>)>
       request_copy_of_output_callback_for_testing_;
 
   // YUV readback pipeline.
   std::unique_ptr<content::ReadbackYUVInterface> yuv_readback_pipeline_;
 
   std::unique_ptr<DelegatedFrameEvictor> delegated_frame_evictor_;
-
-  cc::BeginFrameSource* begin_frame_source_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_DELEGATED_FRAME_HOST_H_