Disable MouseCursorMonitorTest due to flake on Windows.

TBR=sergeyu
BUG=3408

Review URL: https://webrtc-codereview.appspot.com/15589005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6256 4adac7df-926f-26a2-2b94-8c16560cd09d