Update perf page_set to use story_set

tools/perf/page_sets/pathological_mobile_sites.py

 # Copyright 2015 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 telemetry import story
 from telemetry.page import page as page_module
-from telemetry.page import page_set as page_set_module
 from telemetry.page import shared_page_state
 
 
 class PathologicalMobileSitesPage(page_module.Page):
 
   def __init__(self, url, page_set):
     super(PathologicalMobileSitesPage, self).__init__(
         url=url, page_set=page_set, credentials_path='data/credentials.json',
         shared_page_state_class=shared_page_state.SharedMobilePageState)
     self.archive_data_file = 'data/pathological_mobile_sites.json'
 
   def RunPageInteractions(self, action_runner):
     with action_runner.CreateGestureInteraction('ScrollAction'):
       action_runner.ScrollPage()
 
 
-class PathologicalMobileSitesPageSet(page_set_module.PageSet):
+class PathologicalMobileSitesPageSet(story.StorySet):
 
   """Pathologically bad and janky sites on mobile."""
 
   def __init__(self):
     super(PathologicalMobileSitesPageSet, self).__init__(
         archive_data_file='data/pathological_mobile_sites.json',
-        bucket=page_set_module.PARTNER_BUCKET)
+        cloud_storage_bucket=story.PARTNER_BUCKET)
 
     sites = ['http://edition.cnn.com',
              'http://m.espn.go.com/nhl/rankings',
              'http://recode.net',
              'http://sports.yahoo.com/',
              'http://www.latimes.com',
              ('http://www.pbs.org/newshour/bb/'
               'much-really-cost-live-city-like-seattle/#the-rundown'),
              ('http://www.theguardian.com/politics/2015/mar/09/'
               'ed-balls-tory-spending-plans-nhs-charging'),
              'http://www.zdnet.com',
              'http://www.wowwiki.com/World_of_Warcraft:_Mists_of_Pandaria',
              'https://www.linkedin.com/in/linustorvalds']
 
     for site in sites:
       self.AddUserStory(PathologicalMobileSitesPage(site, self))