Disable WebRtcVideoMediaChannelSimulcastTest.SimulcastSend tests on Win (take 2)

In https://webrtc-codereview.appspot.com/35669004/ the wrong
define was used (OS_WIN only exists in Chromium code).

BUG=4135
R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/33799004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@8008 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed