Reenable WebRtcVideoEngineTestFake.SendReceiveBitratesStats under DrMemory.

The uninitialized read has been fixed. Suppressing CL: https://code.google.com/p/webrtc/source/detail?r=6073

BUG=11288120
R=kjellander@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/14529005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6199 4adac7df-926f-26a2-2b94-8c16560cd09d