Revert of perf: Disable mashable.com in tough_ad_cases as it is crashing

tools/perf/page_sets/tough_ad_cases.py

 # Copyright 2015 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 page_sets import repeatable_synthesize_scroll_gesture_shared_state
 
 from telemetry.core import util
 from telemetry.page import page as page_module
 from telemetry import story
 
@@ skipping 171 matching lines @@
     self.AddStory(AdPage('file://tough_ad_cases/'
         'swiffy_webgl_collection.html',
         self, make_javascript_deterministic=False, scroll=scroll))
     self.AddStory(AdPage('http://www.latimes.com', self, scroll=scroll,
         wait_for_interactive_or_better=True))
     self.AddStory(ForbesAdPage('http://www.forbes.com/sites/parmyolson/'
         '2015/07/29/jana-mobile-data-facebook-internet-org/',
         self, scroll=scroll))
     self.AddStory(AdPage('http://androidcentral.com', self, scroll=scroll,
         wait_for_interactive_or_better=True))
-    # Disabled: crbug.com/682349
-    #self.AddStory(AdPage('http://mashable.com', self, scroll=scroll,
-    #    y_scroll_distance_multiplier=0.25))
+    self.AddStory(AdPage('http://mashable.com', self, scroll=scroll,
+        y_scroll_distance_multiplier=0.25))
     self.AddStory(AdPage('http://www.androidauthority.com/'
         'reduce-data-use-turn-on-data-compression-in-chrome-630064/', self,
         scroll=scroll))
     self.AddStory(AdPage(('http://www.cnn.com/2015/01/09/politics/'
                           'nebraska-keystone-pipeline/index.html'),
                          self, scroll=scroll))
     # Disabled: crbug.com/520509
     #self.AddStory(AdPage('http://time.com/3977891/'
     #    'donald-trump-debate-republican/', self, scroll=scroll))
     self.AddStory(AdPage('http://www.theguardian.com/uk', self, scroll=scroll))
     # Disabled: http://crbug.com/597656
     # self.AddStory(AdPage('http://m.tmz.com', self, scroll=scroll,
     #     y_scroll_distance_multiplier=0.25))
     self.AddStory(AdPage('http://androidpolice.com', self, scroll=scroll,
         wait_for_interactive_or_better=True))
 
 
 class ScrollingToughAdCasesPageSet(ToughAdCasesPageSet):
   """Pages for measuring scrolling performance with advertising content."""
 
   def __init__(self):
     super(ScrollingToughAdCasesPageSet, self).__init__(
         scroll=True)