Enable generation of local host candidate.

Source/modules/mediastream/RTCPeerConnection.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 85 matching lines @@
             iceTransports = RTCIceTransportsNone;
         } else if (iceTransportsString == "relay") {
             iceTransports = RTCIceTransportsRelay;
         } else if (iceTransportsString != "all") {
             exceptionState.throwTypeError("Malformed RTCIceTransports");
             return 0;
         }
     }
 
     ArrayValue iceServers;
+    size_t numberOfServers = 0;
+    bool enableLocalhostCandidate = false;
     bool ok = DictionaryHelper::get(configuration, "iceServers", iceServers);
-    if (!ok || iceServers.isUndefinedOrNull()) {
-        exceptionState.throwTypeError("Malformed RTCConfiguration");
-        return 0;
-    }
-
-    size_t numberOfServers;
-    ok = iceServers.length(numberOfServers);
     if (!ok) {
-        exceptionState.throwTypeError("Malformed RTCConfiguration");
-        return 0;
+        v8::Local<v8::Value> iceServersValue;
+        // Failed to parse iceServers as ArrayValue, try it as a scalar.
+        ok = DictionaryHelper::get(configuration, "iceServers", iceServersValue);
+        if (!ok || iceServersValue->IsUndefined()) {
+            // if iceServers is not specified (|ok| is false) or specified as
+            // "undefined", treat it as the special case which generates
+            // localhost candidate.
+            enableLocalhostCandidate = true;
+        } else {
+            exceptionState.throwTypeError("Malformed RTCConfiguration");
+            return 0;
+        }
+    } else {
+        ok = iceServers.length(numberOfServers);
+        if (!ok) {
+            exceptionState.throwTypeError("Malformed RTCConfiguration");
+            return 0;
+        }
     }
 
     RTCBundlePolicy bundlePolicy = RTCBundlePolicyBalanced;
     String bundlePolicyString;
     if (DictionaryHelper::get(configuration, "bundlePolicy", bundlePolicyString)) {
         if (bundlePolicyString == "max-compat") {
             bundlePolicy = RTCBundlePolicyMaxCompat;
         } else if (bundlePolicyString == "max-bundle") {
             bundlePolicy = RTCBundlePolicyMaxBundle;
         } else if (bundlePolicyString != "balanced") {
@@ skipping 10 matching lines @@
         } else if (rtcpMuxPolicyString != "negotiate") {
             exceptionState.throwTypeError("Malformed RTCRtcpMuxPolicy");
             return 0;
         }
     }
 
     RTCConfiguration* rtcConfiguration = RTCConfiguration::create();
     rtcConfiguration->setIceTransports(iceTransports);
     rtcConfiguration->setBundlePolicy(bundlePolicy);
     rtcConfiguration->setRtcpMuxPolicy(rtcpMuxPolicy);
+    rtcConfiguration->setEnableLocalhostCandidate(enableLocalhostCandidate);
 
     for (size_t i = 0; i < numberOfServers; ++i) {
         Dictionary iceServer;
         ok = iceServers.get(i, iceServer);
         if (!ok) {
             exceptionState.throwTypeError("Malformed RTCIceServer");
             return 0;
         }
 
         Vector<String> names;
@@ skipping 678 matching lines @@
 {
     visitor->trace(m_localStreams);
     visitor->trace(m_remoteStreams);
     visitor->trace(m_dataChannels);
     visitor->trace(m_scheduledEvents);
     RefCountedGarbageCollectedEventTargetWithInlineData<RTCPeerConnection>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink