Reenable browse:social:twitter on Mac

tools/perf/page_sets/system_health/browsing_stories.py

 # Copyright 2016 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.
 
 from page_sets.system_health import platforms
 from page_sets.system_health import system_health_story
 
 from page_sets.login_helpers import pinterest_login
 
 from telemetry import decorators
@@ skipping 180 matching lines @@
   SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
 
 
 class TwitterMobileStory(_NewsBrowsingStory):
   NAME = 'browse:social:twitter'
   URL = 'https://www.twitter.com/nasa'
   ITEM_SELECTOR = '.Tweet-text'
   SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
 
 
-@decorators.Disabled('win',  # crbug.com/662971
-                     'mac')  # crbug.com/663025
+@decorators.Disabled('win')  # crbug.com/662971
 class TwitterDesktopStory(_NewsBrowsingStory):
   NAME = 'browse:social:twitter'
   URL = 'https://www.twitter.com/nasa'
   IS_SINGLE_PAGE_APP = True
   ITEM_SELECTOR = '.tweet-text'
   SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
 
 
 class WashingtonPostMobileStory(_NewsBrowsingStory):
   """Progressive website"""
@@ skipping 212 matching lines @@
       inner_save_function = 'document.querySelector(".nameAndIcons")'
       action_runner.WaitForElement(element_function=inner_save_function)
       action_runner.ClickElement(element_function=inner_save_function)
       action_runner.Wait(1)  # Wait to make navigation realistic.
 
     # Close selection.
     x_element_function = ('document.querySelector('
                           '".Button.borderless.close.visible")')
     action_runner.ClickElement(element_function=x_element_function)
     action_runner.Wait(1)  # Wait to make navigation realistic.