smoothness.scrolling_tough_ad_cases to use browser driven scrolls

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 telemetry.core import exceptions
 from telemetry.page import page as page_module
+from telemetry.web_perf import timeline_interaction_record
 from telemetry import story
 
 
 class SwiffyPage(page_module.Page):
 
   def __init__(self, url, page_set):
     super(SwiffyPage, self).__init__(url=url, page_set=page_set,
                                      make_javascript_deterministic=False)
 
   def RunNavigateSteps(self, action_runner):
@@ skipping 35 matching lines @@
     # Give the page one second to become interactive and start scrolling after
     # the timeout regardless of the document's ready state.
     try:
       action_runner.tab.WaitForDocumentReadyStateToBeInteractiveOrBetter(1)
     except exceptions.TimeoutException:
       pass
     # Make sure we have a body element to scroll.
     action_runner.WaitForJavaScriptCondition('document.body !== null')
 
   def RunPageInteractions(self, action_runner):
-    for _ in range(10):
-      with action_runner.CreateGestureInteraction('ScrollAction',
-                                                  repeatable=True):
-        action_runner.ScrollPage(distance=500,
-                                 top_start_ratio=self._top_start_ratio)
-      action_runner.Wait(.25)
-
+    # Set up a browser driven repeating scroll.  The delay between the scrolls
+    # should be unaffected by render thread responsivness (or lack there of).
+    flags = [timeline_interaction_record.REPEATABLE]
+    scroll_command = {
+      'method': 'Input.synthesizeScrollGesture',
+      'params': {
+        'x': 500,

[Sami, 2015/08/17 17:06:44]

Can we compute these to always be the middle of screen? Otherwise this might be
flaky depending on the screen size.

[alex clarke (OOO till 29th), 2015/08/18 13:40:51]

Done.

+        'y': 500,
+        'xDistance': 0,
+        'yDistance': -300,
+        'preventFling': True,
+        'repeatCount': 9,

[Sami, 2015/08/17 17:06:44]

10 assuming we change repeatCount to mean the total number of gestures.

[alex clarke (OOO till 29th), 2015/08/18 13:40:51]

Acknowledged.

+        'repeatDelayMs': 250,
+        'interactionMarkerName':
+            timeline_interaction_record.GetJavaScriptMarker(
+                'Gesture_ScrollAction', flags),
+        }
+      }
+    action_runner.tab.RunInspectorCommand(scroll_command)
 
 class ScrollingForbesPage(ScrollingPage):
 
   def __init__(self, url, page_set):
     # forbes.com uses a strange dynamic transform on the body element,
     # which occasionally causes us to try scrolling from outside the
     # screen. Start at the very top of the viewport to avoid this.
     super(ScrollingForbesPage, self).__init__(
         url=url, page_set=page_set, top_start_ratio=0,
         make_javascript_deterministic=False)
@@ skipping 55 matching lines @@
     self.AddStory(ScrollingPage('http://www.androidauthority.com/'
         'reduce-data-use-turn-on-data-compression-in-chrome-630064/', self))
     self.AddStory(ScrollingPage('http://www.cnn.com/2015/01/09/politics/'
         'nebraska-keystone-pipeline/index.html', self, top_start_ratio=0))
     self.AddStory(ScrollingPage('http://time.com/3977891/'
         'donald-trump-debate-republican/', self))
     self.AddStory(ScrollingPage('http://www.theguardian.com/uk', self))
     self.AddStory(ScrollingPage('http://m.tmz.com', self))
     self.AddStory(ScrollingPage('http://androidpolice.com', self,
         top_start_ratio=0))