Add detection for repeated audio in capturing.

content/renderer/media/media_stream_audio_processor.h

Index: content/renderer/media/media_stream_audio_processor.h
diff --git a/content/renderer/media/media_stream_audio_processor.h b/content/renderer/media/media_stream_audio_processor.h
index 4b74ca0a24090d73f7649b93a36dce24d2f9c62b..356d5989f4dfe221b694c86ef24b04f342d7850c 100644
--- a/content/renderer/media/media_stream_audio_processor.h
+++ b/content/renderer/media/media_stream_audio_processor.h
@@ -14,6 +14,7 @@
 #include "content/common/content_export.h"
 #include "content/public/common/media_stream_request.h"
 #include "content/renderer/media/aec_dump_message_filter.h"
+#include "content/renderer/media/audio_repetition_detector.h"
 #include "content/renderer/media/webrtc_audio_device_impl.h"
 #include "media/base/audio_converter.h"
 #include "third_party/libjingle/source/talk/app/webrtc/mediastreaminterface.h"
@@ -112,7 +113,16 @@ class CONTENT_EXPORT MediaStreamAudioProcessor :
   ~MediaStreamAudioProcessor() override;
 
  private:
+  class AudioRepetitionReporter : public AudioRepetitionDetector {

[Henrik Grunell, 2015/10/20 08:50:16]

Comment on the class.

[Henrik Grunell, 2015/10/20 08:50:16]

Let this class own a detector instead of inheriting.

Also, I saw that the MSAP class is already very large. Put this class in its own
file. I suggest to name it WebRtcAudioRepetitionDetector.

[minyue, 2015/10/23 12:05:23]

Per offline discussion with Tommi, we use base::Callback to let user implement
ReportRepetition. With this, your concern about inheritance also goes away.

+   public:
+    AudioRepetitionReporter(int min_length_ms, size_t max_frames,
+                            const int* look_back_times, size_t num_look_back);
+   private:
+    void ReportRepetition(int look_back_ms) override;
+  };
+
   friend class MediaStreamAudioProcessorTest;
+
   FRIEND_TEST_ALL_PREFIXES(MediaStreamAudioProcessorTest,
                            GetAecDumpMessageFilter);
 
@@ -153,6 +163,9 @@ class CONTENT_EXPORT MediaStreamAudioProcessor :
   // both the capture audio thread and the render audio thread.
   base::subtle::Atomic32 render_delay_ms_;
 
+  // Module to detect and report (to UMA) bit exact audio repetition.
+  scoped_ptr<AudioRepetitionReporter> audio_repetition_reporter_;
+
   // Module to handle processing and format conversion.
   scoped_ptr<webrtc::AudioProcessing> audio_processing_;