Add signaling to support ICE renomination.

webrtc/api/peerconnection.cc

Index: webrtc/api/peerconnection.cc
diff --git a/webrtc/api/peerconnection.cc b/webrtc/api/peerconnection.cc
index c675015ac9bbee705038fa997b716571eb342357..3d4139c940df269fb555e4667ec5d74b87362bf6 100644
--- a/webrtc/api/peerconnection.cc
+++ b/webrtc/api/peerconnection.cc
@@ -470,6 +470,7 @@ bool ExtractMediaSessionOptions(
   session_options->bundle_enabled = rtc_options.use_rtp_mux;
   for (auto& kv : session_options->transport_options) {
     kv.second.ice_restart = rtc_options.ice_restart;
+    kv.second.ice_renomination = rtc_options.ice_renomination;
   }
 
   return true;
@@ -513,14 +514,20 @@ bool ParseConstraintsForAnswer(const MediaConstraintsInterface* constraints,
     session_options->bundle_enabled = true;
   }
 
+  // kIceRestart defaults to false according to spec.
   bool ice_restart = false;
   if (FindConstraint(constraints, MediaConstraintsInterface::kIceRestart,
                      &value, &mandatory_constraints_satisfied)) {
-    // kIceRestart defaults to false according to spec.
-    ice_restart = true;
+    ice_restart = value;

[honghaiz3, 2016/08/11 04:57:58]

This appeared to be wrong before.
Plus this value was never actually used before because transport_options is
empty yet. 

This CL changed the behavior by using this value. 
I think we probably want to remove setting ice_restart here because it is set in
webrtcsession.
WDYT?

[Taylor Brandstetter, 2016/08/11 22:36:50]

You're right; setting the value here (in ParseConstraintsForAnswer) does
nothing, since only the presence of an ICE restart in the offer determines if
there's an ICE restart in the answer. We can remove this.

[honghaiz3, 2016/08/12 18:26:40]

Done.

+  }
+  bool ice_renomination = false;
+  if (FindConstraint(constraints, MediaConstraintsInterface::kIceRenomination,
+                     &value, &mandatory_constraints_satisfied)) {
+    ice_renomination = value;
   }
   for (auto& kv : session_options->transport_options) {
     kv.second.ice_restart = ice_restart;
+    kv.second.ice_renomination = ice_renomination;
   }
 
   if (!constraints) {
@@ -987,6 +994,11 @@ void PeerConnection::CreateOffer(CreateSessionDescriptionObserver* observer,
     options.ice_restart = value;
   }
 
+  if (FindConstraint(constraints, MediaConstraintsInterface::kIceRenomination,
+                     &value, &mandatory_constraints)) {
+    options.ice_renomination = value;
+  }
+
   if (FindConstraint(constraints,
                      MediaConstraintsInterface::kUseRtpMux,
                      &value,
@@ -1649,10 +1661,10 @@ bool PeerConnection::GetOptionsForOffer(
   return true;
 }
 
-void PeerConnection::FinishOptionsForAnswer(
+void PeerConnection::InitializeOptionsForAnswer(
     cricket::MediaSessionOptions* session_options) {
-  // TODO(deadbeef): Once we have transceivers, enumerate them here instead of
-  // ContentInfos.
+  session_options->recv_audio = false;
+  session_options->recv_video = false;
   if (session_->remote_description()) {
     // Initialize the transport_options map.
     for (const cricket::ContentInfo& content :
@@ -1661,6 +1673,12 @@ void PeerConnection::FinishOptionsForAnswer(
           cricket::TransportOptions();
     }
   }
+}
+
+void PeerConnection::FinishOptionsForAnswer(
+    cricket::MediaSessionOptions* session_options) {
+  // TODO(deadbeef): Once we have transceivers, enumerate them here instead of
+  // ContentInfos.
   AddSendStreams(session_options, senders_, rtp_data_channels_);
   session_options->bundle_enabled =
       session_options->bundle_enabled &&
@@ -1683,8 +1701,7 @@ void PeerConnection::FinishOptionsForAnswer(
 bool PeerConnection::GetOptionsForAnswer(
     const MediaConstraintsInterface* constraints,
     cricket::MediaSessionOptions* session_options) {
-  session_options->recv_audio = false;
-  session_options->recv_video = false;
+  InitializeOptionsForAnswer(session_options);
   if (!ParseConstraintsForAnswer(constraints, session_options)) {
     return false;
   }
@@ -1697,8 +1714,7 @@ bool PeerConnection::GetOptionsForAnswer(
 bool PeerConnection::GetOptionsForAnswer(
     const RTCOfferAnswerOptions& options,
     cricket::MediaSessionOptions* session_options) {
-  session_options->recv_audio = false;
-  session_options->recv_video = false;
+  InitializeOptionsForAnswer(session_options);
   if (!ExtractMediaSessionOptions(options, false, session_options)) {
     return false;
   }