Add missing comma.

WATCHLISTS

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Watchlist Rules
 # Refer: http://dev.chromium.org/developers/contributing-code/watchlists
 
 # IMPORTANT: The regular expression filepath is tested against each path using
 # re.search, so it is not usually necessary to add .*.
 
@@ skipping 340 matching lines @@
     'events': [ 'eae+blinkwatch@chromium.org', 'dglazkov+blink@chromium.org', 'blink-reviews-events@chromium.org' ],
     'heap': [ 'ager@chromium.org', 'haraken@chromium.org', 'kouhei+heap@chromium.org' ],
     'html': [ 'dglazkov+blink@chromium.org', 'blink-reviews-html@chromium.org' ],
     'public_api': [ 'abarth@chromium.org', 'jamesr@chromium.org', 'dglazkov+blink@chromium.org' ],
     'workers': [ 'kinuko+worker@chromium.org',
                  'horo+watch@chromium.org',
                  'falken@chromium.org' ],
     'wtf': [ 'abarth@chromium.org',
              'mikhail.pozdnyakov@intel.com',
              'aandrey+blink@chromium.org',
-             'blink-reviews-wtf@chromium.org'
+             'blink-reviews-wtf@chromium.org',
              'mkwst+moarreviews@chromium.org' ],
     'indexed_db': ['dgrogan@chromium.org',
                    'jsbell+idb@chromium.org', 'cmumford@chromium.org'],
     'rendering': [ 'pdr@chromium.org',
                    'eae+blinkwatch@chromium.org',
                    'jchaffraix+rendering@chromium.org',
                    'leviw+renderwatch@chromium.org',
                    'zoltan@webkit.org',
                    'rune+blink@opera.com',
                    'blink-reviews-rendering@chromium.org' ],
@@ skipping 42 matching lines @@
               'skal@google.com',
               'vikasa@google.com' ],
     'css_grid_layout': [ 'svillar@igalia.com', 'jfernandez@igalia.com', 'rego@igalia.com' ],
     'css_flexbox': [ 'cbiesinger@chromium.org' ],
     'battery_status': [ 'timvolodine@chromium.org' ],
     'out_of_process_frames': [ 'dcheng@chromium.org' ],
     'device_light': [ 'timvolodine@chromium.org' ],
     'websockets': [ 'tyoshino+watch@chromium.org', 'yhirano+watch@chromium.org' ],
   },
 }