Add pinned dep for cygwin.

Review URL: https://webrtc-codereview.appspot.com/760005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2676 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/DEPS b/DEPS
index 48dfcb8..c389252 100644
--- a/DEPS
+++ b/DEPS
@@ -83,7 +83,7 @@
   "win": {
     # Use our own, stripped down, version of Cygwin (required by GYP).
     "third_party/cygwin":
-      (Var("googlecode_url") % "webrtc") + "/deps/third_party/cygwin",
+      (Var("googlecode_url") % "webrtc") + "/deps/third_party/cygwin@2672",
 
     # Used by libjpeg-turbo.
     "third_party/yasm/binaries":