Use page_set_module.PageSet instead of story.StorySet

tools/skp/page_sets/skia_googlespreadsheet_desktop.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.
 # pylint: disable=W0401,W0614
 
 
-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 SkiaBuildbotDesktopPage(page_module.Page):
 
   def __init__(self, url, page_set):
     super(SkiaBuildbotDesktopPage, self).__init__(
         url=url,
         page_set=page_set,
         credentials_path='data/credentials.json',
         shared_page_state_class=shared_page_state.SharedDesktopPageState)
     self.archive_data_file = 'data/skia_googlespreadsheet_desktop.json'
 
 
-class SkiaGooglespreadsheetDesktopPageSet(story.StorySet):
+class SkiaGooglespreadsheetDesktopPageSet(page_set_module.PageSet):
 
   """ Pages designed to represent the median, not highly optimized web """
 
   def __init__(self):
     super(SkiaGooglespreadsheetDesktopPageSet, self).__init__(
       archive_data_file='data/skia_googlespreadsheet_desktop.json')
 
     urls_list = [
       # Why: from Tom W's list.
       ('https://docs.google.com/spreadsheets/d/'
        '1YnmSPu-p-1nj-lkWd8q_GRgzjiWzg_6A-HvFYqVoVxI/edit?usp=sharing'),
     ]
 
     for url in urls_list:
       self.AddUserStory(SkiaBuildbotDesktopPage(url, self))