Provide a MouseCursorMonitor::CreateForWindow implementation in *_null.cc

Chromium issue:
https://code.google.com/p/chromium/issues/detail?id=310146

BUG=2551
R=wez@chromium.org

Review URL: https://webrtc-codereview.appspot.com/2759004

Patch from Daniel Nicoara <dnicoara@chromium.org>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5061 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed