Disable RelayServerTest.TestExpiration on Mac.

The test is flaky on Mac.
BUG=4134
TBR=pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/33749004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7992 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/p2p/base/relayserver_unittest.cc b/webrtc/p2p/base/relayserver_unittest.cc
index 0bff039..8c1c0ae 100644
--- a/webrtc/p2p/base/relayserver_unittest.cc
+++ b/webrtc/p2p/base/relayserver_unittest.cc
@@ -486,8 +486,14 @@
   }
 }
 
+// Flaky on Mac, see https://code.google.com/p/webrtc/issues/detail?id=4134
+#if defined(WEBRTC_MAC)
+#define MAYBE_TestExpiration DISABLED_TestExpiration
+#else
+#define MAYBE_TestExpiration TestExpiration
+#endif
 // Verify that a binding expires properly, and rejects send requests.
-TEST_F(RelayServerTest, TestExpiration) {
+TEST_F(RelayServerTest, MAYBE_TestExpiration) {
   Allocate();
   Bind();