Add second batch JS benchmark and code generator

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):
@@ skipping 351 matching lines @@
         url='file://tough_scheduling_cases/sync_scroll_offset.html',
         page_set=page_set)
 
   def RunPageInteractions(self, action_runner):
     interaction = action_runner.BeginGestureInteraction(
         'ScrollBounceAction', is_smooth=True)
     action_runner.ScrollBouncePage()
     interaction.End()
 
 
+class SecondBatchJsPage(ToughSchedulingCasesPage):
+
+  """Why: For testing dynamically loading a large batch of Javascript and
+          running a part of it in response to user input.
+  """
+
+  def __init__(self, page_set, variant='medium'):
+    super(SecondBatchJsPage, self).__init__(
+        url='file://tough_scheduling_cases/second_batch_js.html?%s' % variant,
+        page_set=page_set)
+
+  def RunPageInteractions(self, action_runner):
+    # Do a dummy tap to warm up the synthetic tap code path.
+    action_runner.TapElement(selector='div[id="spinner"]')
+    # Begin the action immediately because we want the page to update smoothly
+    # even while resources are being loaded.
+    action_runner.WaitForJavaScriptCondition('window.__ready !== undefined')
+
+    interaction = action_runner.BeginGestureInteraction(
+        'LoadAction', is_smooth=True)
+    action_runner.ClickElement(selector='input[id="load"]')
+    action_runner.WaitForJavaScriptCondition('window.__ready')
+    # Click one second after the resources have finished loading.
+    action_runner.Wait(1)
+    action_runner.TapElement(selector='input[id="run"]')
+    # Wait a little bit for things to settle.
+    action_runner.Wait(.3)

[rmcilroy, 2015/03/17 13:59:36]

Should we wait on the actual JS to finish here (or does action_runner.TapElement
do that implicitly)?

[Sami, 2015/03/18 14:05:32]

Right, good point. I'll make the test signal when it's done.

+    interaction.End()
+
+
 class ToughSchedulingCasesPageSet(page_set_module.PageSet):
 
   """Tough scheduler latency test cases."""
 
   def __init__(self):
     super(ToughSchedulingCasesPageSet, self).__init__(
         user_agent_type='mobile',
         archive_data_file='data/tough_scheduling_cases.json',
         bucket=page_set_module.INTERNAL_BUCKET)
 
@@ skipping 83 matching lines @@
         bounce=True,
         page_set=self))
       # Why: Scroll bounce with slow handler on desktop, blocks only once until
     # ACK timeout.
     self.AddUserStory(EmptyTouchHandlerPage(
         name='bounce_desktop_slow_handler',
         desktop=True,
         slow_handler=True,
         bounce=True,
         page_set=self))
       # Why: For measuring the latency of scroll-synchronized effects.

[rmcilroy, 2015/03/17 13:59:36]

optional nit - I know it's not your patch, but could you fix the indentation on
some of these comments? 

[Sami, 2015/03/18 14:05:32]

Yeah, those look pretty dire. Fixed.

     self.AddUserStory(SynchronizedScrollOffsetPage(page_set=self))
+    # Why: Test loading a large amount of Javascript.
+    self.AddUserStory(SecondBatchJsPage(page_set=self, variant='light'))
+    self.AddUserStory(SecondBatchJsPage(page_set=self, variant='medium'))
+    self.AddUserStory(SecondBatchJsPage(page_set=self, variant='heavy'))