Change the default rtcp mux policy from negotiate to require.

third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp

Index: third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
diff --git a/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp b/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
index e9a15eac46c3e07401d3a8554b946da93e04e576..3403b8be3865b8a3ef14737fcc0a84cc44b35d17 100644
--- a/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
+++ b/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
@@ -229,10 +229,8 @@ WebRTCIceTransportPolicy iceTransportPolicyFromString(const String& policy) {
 
 WebRTCConfiguration parseConfiguration(ExecutionContext* context,
                                        const RTCConfiguration& configuration,
-                                       ExceptionState& exceptionState,
-                                       RtcpMuxPolicy* selectedRtcpMuxPolicy) {
+                                       ExceptionState& exceptionState) {
   DCHECK(context);
-  DCHECK(selectedRtcpMuxPolicy);
 
   WebRTCIceTransportPolicy iceTransportPolicy = WebRTCIceTransportPolicy::kAll;
   if (configuration.hasIceTransportPolicy()) {
@@ -261,17 +259,12 @@ WebRTCConfiguration parseConfiguration(ExecutionContext* context,
     DCHECK_EQ(bundlePolicyString, "balanced");
   }
 
-  // For the histogram value of "WebRTC.PeerConnection.SelectedRtcpMuxPolicy".
-  *selectedRtcpMuxPolicy = RtcpMuxPolicyDefault;
-  WebRTCRtcpMuxPolicy rtcpMuxPolicy = WebRTCRtcpMuxPolicy::kNegotiate;
+  WebRTCRtcpMuxPolicy rtcpMuxPolicy = WebRTCRtcpMuxPolicy::kRequire;
   if (configuration.hasRtcpMuxPolicy()) {

[foolip, 2016/12/14 19:24:47]

Now that rtcpMuxPolicy has a default value in the IDL, you can remove this
check.

[zhihuang1, 2016/12/15 19:14:28]

Done.

     String rtcpMuxPolicyString = configuration.rtcpMuxPolicy();
-    if (rtcpMuxPolicyString == "require") {
-      *selectedRtcpMuxPolicy = RtcpMuxPolicyRequire;
-      rtcpMuxPolicy = WebRTCRtcpMuxPolicy::kRequire;
-    } else {
+    if (rtcpMuxPolicyString != "require") {

[foolip, 2016/12/14 19:24:47]

To match the above structure, I'd do:

if (rtcpMuxPolicyString == "negotiate") {
  rtcpMuxPolicy = WebRTCRtcpMuxPolicy::kNegotiate;
} else {
  DCHECK_EQ(rtcpMuxPolicyString, "require");
}

[zhihuang1, 2016/12/15 19:14:28]

Done.

       DCHECK_EQ(rtcpMuxPolicyString, "negotiate");
-      *selectedRtcpMuxPolicy = RtcpMuxPolicyNegotiate;
+      rtcpMuxPolicy = WebRTCRtcpMuxPolicy::kNegotiate;
     }
   }
 
@@ -441,11 +434,8 @@ RTCPeerConnection* RTCPeerConnection::create(
     UseCounter::count(context,
                       UseCounter::RTCPeerConnectionConstructorCompliant);
 
-  // Record the RtcpMuxPolicy for histogram
-  // "WebRTC.PeerConnection.SelectedRtcpMuxPolicy".
-  RtcpMuxPolicy selectedRtcpMuxPolicy = RtcpMuxPolicyDefault;
-  WebRTCConfiguration configuration = parseConfiguration(
-      context, rtcConfiguration, exceptionState, &selectedRtcpMuxPolicy);
+  WebRTCConfiguration configuration =
+      parseConfiguration(context, rtcConfiguration, exceptionState);
   if (exceptionState.hadException())
     return 0;
 
@@ -477,9 +467,6 @@ RTCPeerConnection* RTCPeerConnection::create(
   if (exceptionState.hadException())
     return 0;
 
-  peerConnection->m_peerHandler->logSelectedRtcpMuxPolicy(
-      selectedRtcpMuxPolicy);
-
   return peerConnection;
 }
 
@@ -813,9 +800,8 @@ void RTCPeerConnection::updateIce(ExecutionContext* context,
   if (throwExceptionIfSignalingStateClosed(m_signalingState, exceptionState))
     return;
 
-  RtcpMuxPolicy selectedRtcpMuxPolicy = RtcpMuxPolicyDefault;
-  WebRTCConfiguration configuration = parseConfiguration(
-      context, rtcConfiguration, exceptionState, &selectedRtcpMuxPolicy);
+  WebRTCConfiguration configuration =
+      parseConfiguration(context, rtcConfiguration, exceptionState);
 
   if (exceptionState.hadException())
     return;