Update perf page_set to use story_set

tools/perf/page_sets/top_10_mobile.py

 # Copyright 2014 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 Top10MobilePage(page_module.Page):
 
   def __init__(self, url, page_set, run_no_page_interactions):
     super(Top10MobilePage, 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/top_10_mobile.json'
     self._run_no_page_interactions = run_no_page_interactions
 
   def RunPageInteractions(self, action_runner):
     if self._run_no_page_interactions:
       return
     with action_runner.CreateGestureInteraction('ScrollAction'):
       action_runner.ScrollPage()
 
 
-class Top10MobilePageSet(page_set_module.PageSet):
+class Top10MobilePageSet(story.StorySet):
 
   """ Top 10 mobile sites """
 
   def __init__(self, run_no_page_interactions=False):
     super(Top10MobilePageSet, self).__init__(
       archive_data_file='data/top_10_mobile.json',
-      bucket=page_set_module.PARTNER_BUCKET)
+      cloud_storage_bucket=story.PARTNER_BUCKET)
 
     urls_list = [
       # Why: #1 (Alexa) most visited page worldwide, picked a reasonable
       # search term
       'https://www.google.com/#hl=en&q=science',
       # Why: #2 (Alexa) most visited page worldwide, picked the most liked
       # page
       'https://m.facebook.com/rihanna',
       # Why: #3 (Alexa) most visited page worldwide, picked a reasonable
       # search term
@@ skipping 15 matching lines @@
       # Why: #13 (Alexa) most visited page worldwide, picked the first real
       # page
       'http://m.taobao.com/channel/act/mobile/20131111-women.html',
       # Why: #18 (Alexa) most visited page worldwide, picked a reasonable
       # search term
       'http://yandex.ru/touchsearch?text=science',
     ]
 
     for url in urls_list:
       self.AddUserStory(Top10MobilePage(url, self, run_no_page_interactions))