Task Execution Duration metrics added as a new benchmark

tools/perf/page_sets/tough_scheduling_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.page import page as page_module
 from telemetry.page import page_set as page_set_module
 
 
 class ToughSchedulingCasesPage(page_module.Page):
 
   def __init__(self, url, page_set):
     super(ToughSchedulingCasesPage, self).__init__(
-        url=url, page_set=page_set, credentials_path = 'data/credentials.json')
+        url=url, page_set=page_set, credentials_path='data/credentials.json')
     self.user_agent_type = 'mobile'
     self.archive_data_file = 'data/tough_scheduling_cases.json'
 
   def RunSmoothness(self, action_runner):
     interaction = action_runner.BeginGestureInteraction(
         'ScrollAction', is_smooth=True)
     action_runner.ScrollPage()
     interaction.End()
 
+  def RunTaskExecutionTime(self, action_runner):
+    interaction = action_runner.BeginGestureInteraction(
+        'ScrollAction', is_smooth=True)
+    action_runner.ScrollPage()
+    interaction.End()
+
 
 class Page1(ToughSchedulingCasesPage):
 
   """ Why: Simulate oversubscribed main thread """
 
   def __init__(self, page_set):
     super(Page1, self).__init__(
       url='file://tough_scheduling_cases/simple_text_page.html?main_busy',
       page_set=page_set)
 
@@ skipping 443 matching lines @@
       page_set=self))
     # Why: For measuring the latency of scroll-synchronized effects.
     self.AddPage(SynchronizedScrollOffsetPage(page_set=self))
     # Why: Good examples of poor initial scrolling
     self.AddPage(ToughSchedulingCasesPage(
       'http://www.latimes.com',
       self))
     self.AddPage(ToughSchedulingCasesPage(
       'http://m.espn.go.com/nhl/rankings',
        self))