Report metrics about negotiated ciphers.

talk/app/webrtc/peerconnectioninterface.h

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 109 matching lines @@
 
  protected:
   virtual ~StatsObserver() {}
 };
 
 class MetricsObserverInterface : public rtc::RefCountInterface {
  public:
   virtual void IncrementCounter(PeerConnectionMetricsCounter type) = 0;
   virtual void AddHistogramSample(PeerConnectionMetricsName type,
                                   int value) = 0;
+  // TODO(jbauch): Make method abstract when it is implemented by Chromium.
+  virtual void CiphersNegotiated(const std::string& content_name,

[juberti1, 2015/06/06 00:18:40]

This seems very ad-hoc. Can we abstract this into a general API where we can
specify the frequency of string values?

[joachim, 2015/06/08 20:58:40]

Are you thinking about something like
IncrementCounter(PeerConnectionMetricsKey type, const std::string& value);

where 'key' would be 'kPeerConnectionAudioSrtpCipher' or
'kPeerConnectionVideoSslCipher', etc. and 'value' the actual cipher suite?

+                                 const std::string& srtp_cipher,
+                                 const std::string& ssl_cipher) {};
 
  protected:
   virtual ~MetricsObserverInterface() {}
 };
 
 typedef MetricsObserverInterface UMAObserver;
 
 class PeerConnectionInterface : public rtc::RefCountInterface {
  public:
   // See http://dev.w3.org/2011/webrtc/editor/webrtc.html#state-definitions .
@@ skipping 479 matching lines @@
 CreatePeerConnectionFactory(
     rtc::Thread* worker_thread,
     rtc::Thread* signaling_thread,
     AudioDeviceModule* default_adm,
     cricket::WebRtcVideoEncoderFactory* encoder_factory,
     cricket::WebRtcVideoDecoderFactory* decoder_factory);
 
 }  // namespace webrtc
 
 #endif  // TALK_APP_WEBRTC_PEERCONNECTIONINTERFACE_H_