Revert of [Telemetry] Update facebook credential & reenable memory.top_7_stress

tools/perf/page_sets/top_7_stress.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
 
 
 def _GetCurrentLocation(action_runner):
   return action_runner.EvaluateJavaScript('document.location.href')
 
@@ skipping 281 matching lines @@
     action_runner.ScrollPage()
     interaction.End()
 
 
 class FacebookPage(Top7StressPage):
 
   """ Why: top social,Public profile """
 
   def __init__(self, page_set):
     super(FacebookPage, self).__init__(
-      url='https://www.facebook.com/barackobama',
+      url='http://www.facebook.com/barackobama',
       page_set=page_set,
       name='Facebook')
-    self.credentials = 'facebook2'
+    self.credentials = 'facebook'
 
   def RunNavigateSteps(self, action_runner):
     super(FacebookPage, self).RunNavigateSteps(action_runner)
     action_runner.WaitForElement(text='About')
 
   def RunPageInteractions(self, action_runner):
     # Scroll and wait for the next page to be loaded.
     interaction = action_runner.BeginGestureInteraction(
         'ScrollAction', is_smooth=True)
     action_runner.ScrollPage()
@@ skipping 21 matching lines @@
       archive_data_file='data/top_7_stress.json',
       bucket=page_set_module.PARTNER_BUCKET)
 
     self.AddUserStory(GoogleWebSearchPage(self))
     self.AddUserStory(GmailPage(self))
     self.AddUserStory(GoogleCalendarPage(self))
     self.AddUserStory(GooglePlusPage(self))
     self.AddUserStory(BlogspotPage(self))
     self.AddUserStory(WordpressPage(self))
     self.AddUserStory(FacebookPage(self))