Change the default rtcp mux policy from negotiate to require.

third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h

Index: third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h
diff --git a/third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h b/third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h
index c603e7ce128994d6e9dc444f6d649b1c49c06bbc..48b4439ca50d5c1d9f56b94ccb83afae2590e011 100644
--- a/third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h
+++ b/third_party/WebKit/public/platform/WebRTCPeerConnectionHandler.h
@@ -51,15 +51,6 @@ class WebString;
 struct WebRTCConfiguration;
 struct WebRTCDataChannelInit;
 
-// Used to back histogram value of
-// "WebRTC.PeerConnection.SelectedRtcpMuxPolicy", so treat as append-only.
-enum RtcpMuxPolicy {
-  RtcpMuxPolicyRequire,
-  RtcpMuxPolicyNegotiate,
-  RtcpMuxPolicyDefault,
-  RtcpMuxPolicyMax
-};
-
 class WebRTCPeerConnectionHandler {
  public:
   virtual ~WebRTCPeerConnectionHandler() {}
@@ -82,7 +73,6 @@ class WebRTCPeerConnectionHandler {
   virtual WebRTCSessionDescription localDescription() = 0;
   virtual WebRTCSessionDescription remoteDescription() = 0;
   virtual bool updateICE(const WebRTCConfiguration&) = 0;
-  virtual void logSelectedRtcpMuxPolicy(RtcpMuxPolicy) = 0;
 
   // DEPRECATED
   virtual bool addICECandidate(const WebRTCICECandidate&) { return false; }