Remove DISABLED_ON_ macros.

webrtc/voice_engine/test/auto_test/standard/rtp_rtcp_test.cc

Index: webrtc/voice_engine/test/auto_test/standard/rtp_rtcp_test.cc
diff --git a/webrtc/voice_engine/test/auto_test/standard/rtp_rtcp_test.cc b/webrtc/voice_engine/test/auto_test/standard/rtp_rtcp_test.cc
index 14dca27d1cb81f3c936072f626b2515cc1c730f7..6efa55d516bdd1730c5b44cd20eca8bd1f75f7bd 100644
--- a/webrtc/voice_engine/test/auto_test/standard/rtp_rtcp_test.cc
+++ b/webrtc/voice_engine/test/auto_test/standard/rtp_rtcp_test.cc
@@ -101,8 +101,7 @@ TEST_F(RtpRtcpTest, RemoteRtcpCnameHasPropagatedToRemoteSide) {
   EXPECT_STREQ(RTCP_CNAME, char_buffer);
 }
 
-// Flakily hangs on Linux. code.google.com/p/webrtc/issues/detail?id=2178.
-TEST_F(RtpRtcpTest, DISABLED_ON_LINUX(SSRCPropagatesCorrectly)) {
+TEST_F(RtpRtcpTest, SSRCPropagatesCorrectly) {
   unsigned int local_ssrc = 1234;
   EXPECT_EQ(0, voe_base_->StopSend(channel_));
   EXPECT_EQ(0, voe_rtp_rtcp_->SetLocalSSRC(channel_, local_ssrc));