Migrate from telemetry PageSet -> StorySet.

tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/video_instrumented.py

Index: tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/video_instrumented.py
diff --git a/tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/video_instrumented.py b/tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/video_instrumented.py
index 74653175a8b72d8ddc6d1916cbf9df94025f18c3..8cd993b2b5a6d4a73beeea678693c0da4d225198 100644
--- a/tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/video_instrumented.py
+++ b/tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/video_instrumented.py
@@ -3,23 +3,23 @@
 # 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 VideoFramePageSet(page_set_module.PageSet):
+class VideoFrameStorySet(story.StorySet):
   """Chrome proxy video tests: verify frames of transcoded videos"""
   def __init__(self):
-    super(VideoFramePageSet, self).__init__()
+    super(VideoFrameStorySet, self).__init__()
     for url in [
         'http://check.googlezip.net/cacheable/video/buck_bunny_640x360_24fps_video.html',
         'http://check.googlezip.net/cacheable/video/buck_bunny_60fps_video.html',
         ]:
-      self.AddUserStory(page_module.Page(url, self))
+      self.AddStory(page_module.Page(url, self))
 
-class VideoAudioPageSet(page_set_module.PageSet):
+class VideoAudioStorySet(story.StorySet):
   """Chrome proxy video tests: verify audio of transcoded videos"""
   def __init__(self):
-    super(VideoAudioPageSet, self).__init__()
+    super(VideoAudioStorySet, self).__init__()
     for url in [
         'http://check.googlezip.net/cacheable/video/buck_bunny_640x360_24fps_audio.html',
         ]:
-      self.AddUserStory(page_module.Page(url, self))
+      self.AddStory(page_module.Page(url, self))