Introduce PageCyclerStory and let the stories wait for onload+TTI

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 page_sets import page_cycler_story
+from telemetry import story
 from telemetry.page import cache_temperature as cache_temperature_module
-from telemetry.page import page as page_module
 from telemetry.page import shared_page_state
-from telemetry import story
 
 
-class IntlKoThViPage(page_module.Page):
+class IntlKoThViPage(page_cycler_story.PageCyclerStory):
 
   def __init__(self, url, page_set, cache_temperature=None):
     super(IntlKoThViPage, self).__init__(
         url=url, page_set=page_set,
         shared_page_state_class=shared_page_state.SharedDesktopPageState,
         cache_temperature=cache_temperature)
 
 
 class IntlKoThViPageSet(story.StorySet):
 
@@ skipping 26 matching lines @@
       'http://www.chosun.com/',
       'http://www.danawa.com/',
       # Why: #10 site in Thailand
       'http://pantip.com/',
       'http://thaimisc.com/'
     ]
 
     for url in urls_list:
       for temp in cache_temperatures:
         self.AddStory(IntlKoThViPage(url, self, cache_temperature=temp))