Update perf page_set to use story_set

tools/perf/page_sets/intl_ko_th_vi.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 shared_page_state
-from telemetry.page import page as page_module
-from telemetry.page import page_set as page_set_module
 
 
 class IntlKoThViPage(page_module.Page):
 
   def __init__(self, url, page_set):
     super(IntlKoThViPage, self).__init__(
         url=url, page_set=page_set,
         shared_page_state_class=shared_page_state.SharedDesktopPageState)
     self.archive_data_file = 'data/intl_ko_th_vi.json'
 
 
-class IntlKoThViPageSet(page_set_module.PageSet):
+class IntlKoThViPageSet(story.StorySet):
 
   """ Popular pages in Korean, Thai and Vietnamese. """
 
   def __init__(self):
     super(IntlKoThViPageSet, self).__init__(
       archive_data_file='data/intl_ko_th_vi.json',
-      bucket=page_set_module.PARTNER_BUCKET)
+      cloud_storage_bucket=story.PARTNER_BUCKET)
 
     urls_list = [
       # Why: #7 site in Vietnam
       'http://us.24h.com.vn/',
       # Why: #6 site in Vietnam
       'http://vnexpress.net/',
       # Why: #18 site in Vietnam
       'http://vietnamnet.vn/',
       # Why: #5 site in Vietnam
       # pylint: disable=C0301
       'http://news.zing.vn/the-gioi/ba-dam-thep-margaret-thatcher-qua-doi/a312895.html#home_noibat1',
       'http://kenh14.vn/home.chn',
       # Why: #5 site in Korea
       'http://www.naver.com/',
       # Why: #9 site in Korea
       'http://www.daum.net/',
       # Why: #25 site in Korea
       'http://www.donga.com/',
       'http://www.chosun.com/',
       'http://www.danawa.com/',
       # Why: #10 site in Thailand
       'http://pantip.com/',
       'http://thaimisc.com/'
     ]
 
     for url in urls_list:
       self.AddUserStory(IntlKoThViPage(url, self))