Adding unit test to ensure TURN server priorities are unique.

talk/app/webrtc/peerconnection_unittest.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * 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 notice,
@@ skipping 2004 matching lines @@
   PeerConnectionInterface::IceServers servers;
   PeerConnectionInterface::IceServer server;
   server.urls.push_back("stun:hostname");
   server.urls.push_back("turn:hostname");
   servers.push_back(server);
   EXPECT_TRUE(webrtc::ParseIceServers(servers, &stun_servers_, &turn_servers_));
   EXPECT_EQ(1U, stun_servers_.size());
   EXPECT_EQ(1U, turn_servers_.size());
 }
 
+// Ensure that TURN servers are given unique priorities,
+// so that their resulting candidates have unique priorities.
+TEST_F(IceServerParsingTest, TurnServerPrioritiesUnique) {
+  PeerConnectionInterface::IceServers servers;
+  PeerConnectionInterface::IceServer server;
+  server.urls.push_back("turn:hostname");
+  server.urls.push_back("turn:hostname2");
+  servers.push_back(server);
+  EXPECT_TRUE(webrtc::ParseIceServers(servers, &stun_servers_, &turn_servers_));
+  EXPECT_EQ(2U, turn_servers_.size());
+  EXPECT_NE(turn_servers_[0].priority, turn_servers_[1].priority);
+}
+
 #endif // if !defined(THREAD_SANITIZER)