Add optimization for CHROMIUM_subscribe_uniform extension.

content/browser/renderer_host/render_widget_host_impl.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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 804 matching lines @@
   scoped_ptr<InputRouter> input_router_;
 
   scoped_ptr<TimeoutMonitor> hang_monitor_timeout_;
 
 #if defined(OS_WIN)
   std::list<HWND> dummy_windows_for_activation_;
 #endif
 
   RenderWidgetHostLatencyTracker latency_tracker_;
 
-  bool subscribe_uniform_enabled_;
-
   int next_browser_snapshot_id_;
   typedef std::map<int,
       base::Callback<void(const unsigned char*, size_t)> > PendingSnapshotMap;
   PendingSnapshotMap pending_browser_snapshots_;
 
   base::WeakPtrFactory<RenderWidgetHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_