Fix watchlist definition for clipboard.

BUG=none
TEST=python $DEPOT_TOOLS/watchlists.py clipboard matches

Review URL: http://codereview.chromium.org/8574077

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110589 0039d316-1c4b-4281-b951-d872f2087c98

WATCHLISTS

@@ -303,10 +303,7 @@
       'filepath': 'base/message_.*'
     },
     'clipboard': {
-      'filepath': 'clipboard',
-      'filepath': 'dnd',
-      'filepath': 'drag',
-      'filepath': 'drop',
+      'filepath': 'clipboard|dnd|drag|drop',
     },
   },