WebmMuxer: add Pause()/Resume() methods and internal time-in-pause

media/muxers/webm_muxer.h

Index: media/muxers/webm_muxer.h
diff --git a/media/muxers/webm_muxer.h b/media/muxers/webm_muxer.h
index 227ce5622fddc9d1ec65921d0fe1e87cd266dd4b..47141844978f5697cf8037cbd4b2ede9d3360f27 100644
--- a/media/muxers/webm_muxer.h
+++ b/media/muxers/webm_muxer.h
@@ -15,6 +15,7 @@
 #include "base/strings/string_piece.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
+#include "base/timer/elapsed_timer.h"
 #include "media/base/media_export.h"
 #include "media/base/video_codecs.h"
 #include "third_party/libwebm/source/mkvmuxer.hpp"
@@ -63,6 +64,9 @@ class MEDIA_EXPORT WebmMuxer : public NON_EXPORTED_BASE(mkvmuxer::IMkvWriter) {
                       scoped_ptr<std::string> encoded_data,
                       base::TimeTicks timestamp);
 
+  void Pause();
+  void Resume();
+
  private:
   friend class WebmMuxerTest;
 
@@ -103,6 +107,10 @@ class MEDIA_EXPORT WebmMuxer : public NON_EXPORTED_BASE(mkvmuxer::IMkvWriter) {
   base::TimeTicks first_frame_timestamp_;
   base::TimeDelta most_recent_timestamp_;
 
+  // Variables to measure and accumulate, respectively, the time in pause state.
+  scoped_ptr<base::ElapsedTimer> elapsed_time_in_pause_;
+  base::TimeDelta total_time_in_pause_;
+
   // TODO(ajose): Change these when support is added for multiple tracks.
   // http://crbug.com/528523
   const bool has_video_;