Make credential_path a page attribute instead of page_set attribute.

tools/perf/page_sets/tough_energy_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 ToughEnergyCasesPage(page_module.Page):
 
   def __init__(self, url, page_set):
-    super(ToughEnergyCasesPage, self).__init__(url=url, page_set=page_set)
-    self.credentials_path = 'data/credentials.json'
+    super(ToughEnergyCasesPage, self).__init__(
+        url=url, page_set=page_set, credentials_path = 'data/credentials.json')
 
 class CodePenPage(ToughEnergyCasesPage):
 
   def __init__(self, url, page_set):
     super(CodePenPage, self).__init__(url, page_set)
     self.credentials = 'codepen'
 
 
 class GooglePage(ToughEnergyCasesPage):
 
   def __init__(self, url, page_set):
     super(GooglePage, self).__init__(
         url=url,
         page_set=page_set)
     self.credentials = 'google'
 
   def RunNavigateSteps(self, action_runner):
     action_runner.NavigateToPage(self)
     action_runner.WaitForJavaScriptCondition(
         'window.gmonkey !== undefined &&'
         'document.getElementById("gb") !== null')
 
 
 class ToughEnergyCasesPageSet(page_set_module.PageSet):
   """Pages for measuring Chrome power draw."""
 
   def __init__(self):
     super(ToughEnergyCasesPageSet, self).__init__(
         archive_data_file='data/tough_energy_cases.json',
-        bucket=page_set_module.PUBLIC_BUCKET,
-        credentials_path='data/credentials.json')
+        bucket=page_set_module.PUBLIC_BUCKET)
 
     # Why: productivity, top google properties
     self.AddPage(GooglePage('https://mail.google.com/mail/', self))
 
     # Disabled: pegs CPU too much to get meaningful results.
     # Why: Image constantly changed in the background, above the fold
     # self.AddPage(CodePenPage(
     #     'http://codepen.io/testificate364/debug/eIutG', self))
 
     # Disabled: pegs CPU too much to get meaningful results.
@@ skipping 64 matching lines @@
     # self.AddPage(CodePenPage(
     #     'http://codepen.io/testificate364/debug/ckItK', self))
 
     # Why: flash video
     self.AddPage(CodePenPage(
         'http://codepen.io/testificate364/debug/slBue', self))
 
     # Why: Blank page in the foreground
     self.AddPage(CodePenPage(
         'http://codepen.io/testificate364/debug/HdIgr', self))