Fix WATCHLISTS entry for downloads_ui.

R=benjhayden@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/1383133002

Cr-Commit-Position: refs/heads/master@{#352340}

WATCHLISTS

@@ -323,7 +323,7 @@
       'filepath': 'chrome/browser/resources/downloads/|' \
                   'chrome/browser/ui/webui/.*downloads|' \
                   'chrome/browser/ui/views/download/|' \
-                  'chrome/browser/ui/cocoa/download/|' \
+                  'chrome/browser/ui/cocoa/download/'
     },
     'drive': {
       'filepath': 'chrome/browser/chromeos/drive/|' \