Tab capture: do 200 rendundant captures of static content.

content/browser/renderer_host/media/web_contents_video_capture_device.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_MEDIA_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
@@ skipping 56 matching lines @@
   Name device_name_;
   const scoped_ptr<Impl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsVideoCaptureDevice);
 };
 
 // Filters a sequence of events to achieve a target frequency.
 class CONTENT_EXPORT SmoothEventSampler {
  public:
   explicit SmoothEventSampler(base::TimeDelta capture_period,
-                              bool events_are_reliable);
+                              bool events_are_reliable,
+                              int redundant_capture_goal);
 
   // Add a new event to the event history, and return whether it ought to be
   // sampled per to the sampling frequency limit. Even if this method returns
   // true, the event is not recorded as a sample until RecordSample() is called.
   bool AddEventAndConsiderSampling(base::Time now);
 
   // Operates on the last event added by AddEventAndConsiderSampling(), marking
   // it as sampled. After this point we are current in the stream of events, as
   // we have sampled the most recent event.
   void RecordSample();
 
   // Returns true if, at time |now|, sampling should occur because too much time
   // will have passed relative to the last event and/or sample.
   bool IsOverdueForSamplingAt(base::Time now) const;
 
   base::Time GetLastSampledEvent();
 
  private:
   const bool events_are_reliable_;
   const base::TimeDelta capture_period_;
+  const int redundant_capture_goal_;
   base::Time current_event_;
   base::Time last_sample_;
+  int last_sample_count_;
   DISALLOW_COPY_AND_ASSIGN(SmoothEventSampler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_