Bug 1189030 - Add pref "media.peerconnection.ice.relay_only" (default=false). r=jesup

--HG--
extra : transplant_source : 1%D5%AC%F1%FA%EB%0B%C2%90%8A%83DtVz-L%2C%CC%14

dom/media/PeerConnection.js

@@ -323,6 +323,12 @@ RTCPeerConnection.prototype = {
   __init: function(rtcConfig) {
     this._winID = this._win.QueryInterface(Ci.nsIInterfaceRequestor)
     .getInterface(Ci.nsIDOMWindowUtils).currentInnerWindowID;
+    // TODO: Update this code once we support pc.setConfiguration, to track
+    // setting from content independently from pref (Bug 1181768).
+    if (rtcConfig.iceTransportPolicy == "all" &&
+        Services.prefs.getBoolPref("media.peerconnection.ice.relay_only")) {
+      rtcConfig.iceTransportPolicy = "relay";
+    }
     if (!rtcConfig.iceServers ||
         !Services.prefs.getBoolPref("media.peerconnection.use_document_iceservers")) {
       try {

modules/libpref/init/all.js

@@ -398,6 +398,7 @@ pref("media.peerconnection.default_iceservers", "[]");
 pref("media.peerconnection.ice.loopback", false); // Set only for testing in offline environments.
 pref("media.peerconnection.ice.tcp", false);
 pref("media.peerconnection.ice.link_local", false); // Set only for testing IPV6 in networks that don't assign IPV6 addresses
+pref("media.peerconnection.ice.relay_only", false); // Limit candidates to TURN
 pref("media.peerconnection.use_document_iceservers", true);
 pref("media.peerconnection.identity.enabled", true);
 pref("media.peerconnection.identity.timeout", 10000);