PeerConnection[Interface]::GetStats(RTCStatsCollectorCallback*) added.

webrtc/api/peerconnectioninterface.h

Index: webrtc/api/peerconnectioninterface.h
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index f5d8c63b671921146e69a170eb5a7916f2340fb6..a04e53e2ac935f54ed5bf0398de456285a99f106 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -60,6 +60,7 @@
 #include "webrtc/api/dtmfsenderinterface.h"
 #include "webrtc/api/jsep.h"
 #include "webrtc/api/mediastreaminterface.h"
+#include "webrtc/api/rtcstatscollector.h"
 #include "webrtc/api/rtpreceiverinterface.h"
 #include "webrtc/api/rtpsenderinterface.h"
 #include "webrtc/api/statstypes.h"
@@ -440,6 +441,12 @@ class PeerConnectionInterface : public rtc::RefCountInterface {
   virtual bool GetStats(StatsObserver* observer,
                         MediaStreamTrackInterface* track,
                         StatsOutputLevel level) = 0;
+  // Gets stats using the new stats collection API, see webrtc/api/stats/. These
+  // will replace old stats collection API when the new API has matured enough.
+  // TODO(hbos): Default implementation that does nothing only exists as to not
+  // break third party projects. As soon as they have been updated this should
+  // be changed to "= 0;".
+  virtual void GetStats(RTCStatsCollectorCallback* callback) {}
 
   virtual rtc::scoped_refptr<DataChannelInterface> CreateDataChannel(
       const std::string& label,