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 2842025d358a1912fb84c11646b1e5bf32707d0e..285bcb6b657629f8942da32b6681712fb43d774a 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 setConfiguration(const WebRTCConfiguration&) = 0;
-  virtual void logSelectedRtcpMuxPolicy(RtcpMuxPolicy) = 0;
 
   // DEPRECATED
   virtual bool addICECandidate(const WebRTCICECandidate&) { return false; }