Add the URL attribute to cricket::Candiate.

webrtc/p2p/base/stunport_unittest.cc

Index: webrtc/p2p/base/stunport_unittest.cc
diff --git a/webrtc/p2p/base/stunport_unittest.cc b/webrtc/p2p/base/stunport_unittest.cc
index aa708c1ba196533a88d9b353e1f52671bfa8bada..88f046c53752505bbfa6a3cc0fbdb6cd90d4528c 100644
--- a/webrtc/p2p/base/stunport_unittest.cc
+++ b/webrtc/p2p/base/stunport_unittest.cc
@@ -201,6 +201,8 @@ TEST_F(StunPortTest, TestPrepareAddress) {
   EXPECT_TRUE_SIMULATED_WAIT(done(), kTimeoutMs, fake_clock);
   ASSERT_EQ(1U, port()->Candidates().size());
   EXPECT_TRUE(kLocalAddr.EqualIPs(port()->Candidates()[0].address()));
+  std::string expected_server_url = "stun:" + kStunAddr1.ToString();

[Taylor Brandstetter, 2017/02/10 01:58:46]

nit: This test relies on SocketAddress::ToString()'s implementation not
changing. It may be better to do:

CreateStunPort(rtc::SocketAddress("127.0.0.1", 5000));
...
std::string expected_server_url = "stun:127.0.0.1:5000";

So that the test expectation is more explicit.

[Zhi Huang, 2017/02/10 06:45:50]

Agreed.
If we expect that the ToString() might change, then I'll change the code that
re-constructs the url as well because it also use the ToString() method.

+  EXPECT_EQ(port()->Candidates()[0].url(), expected_server_url);
 
   // TODO: Add IPv6 tests here, once either physicalsocketserver supports
   // IPv6, or this test is changed to use VirtualSocketServer.