Reenable Flipboard story 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 114 matching lines @@
   IS_SINGLE_PAGE_APP = True
   ITEM_SELECTOR = '.grad-top'
   ITEM_SCROLL_REPEAT = 4
   SUPPORTED_PLATFORMS = platforms.MOBILE_ONLY
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     return possible_browser.platform.IsSvelte()  # crbug.com/668097
 
 
-@decorators.Disabled('mac') # crbug.com/663025
 class FlipboardDesktopStory(_NewsBrowsingStory):
   NAME = 'browse:news:flipboard'
   URL = 'https://flipboard.com/explore'
   IS_SINGLE_PAGE_APP = True
   ITEM_SELECTOR = '.cover-image'
   SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
 
 
 # crbug.com/657665 for win and mac, crbug.com/665007 for linux
 @decorators.Disabled('win', 'linux', 'yosemite', 'elcapitan')
@@ skipping 281 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.