Update perf page_set to use story_set

tools/perf/page_sets/tough_animation_cases.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
 
 
 class ToughAnimationCasesPage(page_module.Page):
 
   def __init__(self, url, page_set, need_measurement_ready):
     super(ToughAnimationCasesPage, self).__init__(url=url, page_set=page_set)
     self.archive_data_file = 'data/tough_animation_cases.json'
     self._need_measurement_ready = need_measurement_ready
 
   def RunNavigateSteps(self, action_runner):
     super(ToughAnimationCasesPage, self).RunNavigateSteps(action_runner)
     if self._need_measurement_ready:
       action_runner.WaitForJavaScriptCondition('window.measurementReady')
 
   def RunPageInteractions(self, action_runner):
     with action_runner.CreateInteraction('ToughAnimation'):
       action_runner.Wait(10)
 
-class ToughAnimationCasesPageSet(page_set_module.PageSet):
+class ToughAnimationCasesPageSet(story.StorySet):
 
   """
   Description: A collection of animation performance tests
   """
 
   def __init__(self):
     super(ToughAnimationCasesPageSet, self).__init__(
       archive_data_file='data/tough_animation_cases.json',
-      bucket=page_set_module.PARTNER_BUCKET)
+      cloud_storage_bucket=story.PARTNER_BUCKET)
 
     urls_list_one = [
       # Why: Tests the balls animation implemented with SVG animations.
       'file://tough_animation_cases/balls_svg_animations.html',
       # Why: Tests the balls animation implemented with Javascript and canvas.
       'file://tough_animation_cases/balls_javascript_canvas.html',
       # Why: Tests the balls animation implemented with Javascript and CSS.
       'file://tough_animation_cases/balls_javascript_css.html',
       # Why: Tests the balls animation implemented with CSS keyframe animations.
       'file://tough_animation_cases/balls_css_keyframe_animations.html',
@@ skipping 211 matching lines @@
       'file://tough_animation_cases/mix_blend_mode_propagating_isolation.html',
 
       # Disabled: crbug.com/350692
       # Why: Login page is slow because of ineffecient transform operations.
       # 'http://ie.microsoft.com/testdrive/performance/robohornetpro/',
     ]
 
     for url in urls_list_two:
       self.AddUserStory(ToughAnimationCasesPage(url, self,
                                            need_measurement_ready=False))