Revert of Moving MediaStreamSignaling logic into PeerConnection.

talk/app/webrtc/statscollector.h

Index: talk/app/webrtc/statscollector.h
diff --git a/talk/app/webrtc/statscollector.h b/talk/app/webrtc/statscollector.h
index 714f15a4012e42bc7e3c2d55dc2c2935176a2ba1..add26c6465eee0634237d8a90caf39d175f0c52f 100644
--- a/talk/app/webrtc/statscollector.h
+++ b/talk/app/webrtc/statscollector.h
@@ -43,8 +43,6 @@
 
 namespace webrtc {
 
-class PeerConnection;
-
 // Conversion function to convert candidate type string to the corresponding one
 // from  enum RTCStatsIceCandidateType.
 const char* IceCandidateTypeToStatsType(const std::string& candidate_type);
@@ -59,9 +57,9 @@
 
 class StatsCollector {
  public:
-  // The caller is responsible for ensuring that the pc outlives the
+  // The caller is responsible for ensuring that the session outlives the
   // StatsCollector instance.
-  explicit StatsCollector(PeerConnection* pc);
+  explicit StatsCollector(WebRtcSession* session);
   virtual ~StatsCollector();
 
   // Adds a MediaStream with tracks that can be used as a |selector| in a call
@@ -153,8 +151,8 @@
   // A collection for all of our stats reports.
   StatsCollection reports_;
   TrackIdMap track_ids_;
-  // Raw pointer to the peer connection the statistics are gathered from.
-  PeerConnection* const pc_;
+  // Raw pointer to the session the statistics are gathered from.
+  WebRtcSession* const session_;
   double stats_gathering_started_;
   cricket::ProxyTransportMap proxy_to_transport_;