Migrate from telemetry PageSet -> StorySet.

tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/reenable_after_bypass.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.page import page as page_module
-from telemetry.page import page_set as page_set_module
+from telemetry import story
 
 
 class ReenableAfterBypassPage(page_module.Page):
   """A test page for the re-enable after bypass tests.
 
   Attributes:
       bypass_seconds_min: The minimum number of seconds that the bypass
           triggered by loading this page should last.
       bypass_seconds_max: The maximum number of seconds that the bypass
           triggered by loading this page should last.
   """
 
   def __init__(self,
                url,
                page_set,
                bypass_seconds_min,
                bypass_seconds_max):
     super(ReenableAfterBypassPage, self).__init__(url=url, page_set=page_set)
     self.bypass_seconds_min = bypass_seconds_min
     self.bypass_seconds_max = bypass_seconds_max
 
 
-class ReenableAfterBypassPageSet(page_set_module.PageSet):
+class ReenableAfterBypassStorySet(story.StorySet):
   """ Chrome proxy test sites """
 
   def __init__(self):
-    super(ReenableAfterBypassPageSet, self).__init__()
+    super(ReenableAfterBypassStorySet, self).__init__()
 
     # Test page for "Chrome-Proxy: block=0". Loading this page should cause all
     # data reduction proxies to be bypassed for one to five minutes.
-    self.AddUserStory(ReenableAfterBypassPage(
+    self.AddStory(ReenableAfterBypassPage(
         url="http://check.googlezip.net/block",
         page_set=self,
         bypass_seconds_min=60,
         bypass_seconds_max=300))