Updates exception and adds rety to ExecuteAsyncJavaScript

chrome/test/media_router/telemetry/benchmarks/pagesets/media_router_perf_pages.py

 # Copyright 2016 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.
 
 import utils
 
 from telemetry import page
 from telemetry import story
 from benchmarks.pagesets import media_router_page
 from telemetry.core import exceptions
@@ skipping 107 matching lines @@
 
       action_runner.Wait(5)
       action_runner.ExecuteJavaScript('collectPerfData();')
       action_runner.Wait(SESSION_TIME)
       # Stop session
       self.ExecuteAsyncJavaScript(
           action_runner,
           'stopSession();',
           lambda: not action_runner.EvaluateJavaScript('currentSession'),
           'Failed to stop session',
-          timeout=30)
+          timeout=60, retry=3)
 
 
 class CastMirroringPage(media_router_page.CastPage):
   """Cast page to mirror a tab to Chromecast device."""
 
   def __init__(self, page_set):
     super(CastMirroringPage, self).__init__(
         page_set=page_set,
         url='file://mirroring.html',
         shared_page_state_class=SharedState)
@@ skipping 23 matching lines @@
       action_runner.TapElement(selector='#start_session_button')
       self._WaitForResult(
           action_runner,
           lambda: len(action_runner.tab.browser.tabs) >= 2,
           'MR dialog never showed up.')
 
       for tab in action_runner.tab.browser.tabs:
         if tab.url == 'chrome://media-router/':
           self.WaitUntilDialogLoaded(action_runner, tab)
           if not self.CheckIfExistingRoute(tab, sink_name):
-            raise page.page_test.Failure('Failed to start mirroring session.')
+            raise RuntimeError('Failed to start mirroring session.')
       action_runner.ExecuteJavaScript('collectPerfData();')
       action_runner.Wait(SESSION_TIME)
       self.CloseExistingRoute(action_runner, sink_name)
 
 
 class MediaRouterDialogPageSet(story.StorySet):
   """Pageset for media router dialog latency tests."""
 
   def __init__(self):
     super(MediaRouterDialogPageSet, self).__init__(
@@ skipping 12 matching lines @@
     self.AddStory(CastMirroringPage(self))
 
 
 class CPUMemoryPageSet(story.StorySet):
   """Pageset to get baseline CPU and memory usage."""
 
   def __init__(self):
     super(CPUMemoryPageSet, self).__init__(
         cloud_storage_bucket=story.PARTNER_BUCKET)
     self.AddStory(CastIdlePage(self))