Enable generation of local host candidate when RTCConfiguration is null.

content/renderer/media/rtc_peer_connection_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/rtc_peer_connection_handler.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 167 matching lines @@
     description->ToString(sdp);
     *type = description->type();
   }
 }
 
 // Converter functions from WebKit types to WebRTC types.
 
 void GetNativeRtcConfiguration(
     const blink::WebRTCConfiguration& blink_config,
     webrtc::PeerConnectionInterface::RTCConfiguration* webrtc_config) {
-  if (blink_config.isNull() || !webrtc_config)
+  if (!webrtc_config)
     return;
+
+  // When we don't have WebRTCConfiguration, treat it as a special case where we
+  // should generate local host candidate. This will only be honored if
+  // enable_multiple_routes is disabled.
+  if (blink_config.isNull()) {
+    webrtc_config->enable_localhost_ice_candidate = true;
+    return;
+  }
+
+  webrtc_config->enable_localhost_ice_candidate =

[juberti, 2015/08/28 00:24:49]

What does this do, exactly?

+      blink_config.enableLocalhostCandidate();
+
   for (size_t i = 0; i < blink_config.numberOfServers(); ++i) {
     webrtc::PeerConnectionInterface::IceServer server;
     const blink::WebRTCICEServer& webkit_server =
         blink_config.server(i);
     server.username =
         base::UTF16ToUTF8(base::StringPiece16(webkit_server.username()));
     server.password =
         base::UTF16ToUTF8(base::StringPiece16(webkit_server.credential()));
     server.uri = webkit_server.uri().spec();
     webrtc_config->servers.push_back(server);
@@ skipping 1411 matching lines @@
 }
 
 void RTCPeerConnectionHandler::ResetUMAStats() {
   DCHECK(thread_checker_.CalledOnValidThread());
   num_local_candidates_ipv6_ = 0;
   num_local_candidates_ipv4_ = 0;
   ice_connection_checking_start_ = base::TimeTicks();
   memset(ice_state_seen_, 0, sizeof(ice_state_seen_));
 }
 }  // namespace content