Add UMA stats for SharedWorker in RenderProcessHostImpl.

content/browser/renderer_host/render_process_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_BROWSER_RENDER_PROCESS_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_IMPL_H_
 
 #include <map>
 #include <queue>
 #include <string>
@@ skipping 413 matching lines @@
 
 #if defined(ENABLE_WEBRTC)
   base::Callback<void(const std::string&)> webrtc_log_message_callback_;
 #endif
 
   // Message filter and dispatcher for screen orientation.
   ScreenOrientationDispatcherHost* screen_orientation_dispatcher_host_;
 
   int worker_ref_count_;
 
+  // Records the time when the process starts surviving for workers for UMA.
+  base::TimeTicks survive_for_worker_start_time_;
+
 #if defined(USE_MOJO)
   scoped_ptr<MojoChannelInit> mojo_channel_init_;
 #endif
 
   base::WeakPtrFactory<RenderProcessHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderProcessHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_IMPL_H_