Changed so that a new resources bundle will always downloaded if the currently downloaded version differs from the one in DEPS.
BUG=
TEST=gclient sync with different revisions in the /resources/webrtc-resouces-revision file.
Review URL: http://webrtc-codereview.appspot.com/330033
git-svn-id: http://webrtc.googlecode.com/svn/trunk@1343 4adac7df-926f-26a2-2b94-8c16560cd09d