smoothness.scrolling_tough_ad_cases to use browser driven scrolls

tools/perf/page_sets/tough_ad_cases.py

Index: tools/perf/page_sets/tough_ad_cases.py
diff --git a/tools/perf/page_sets/tough_ad_cases.py b/tools/perf/page_sets/tough_ad_cases.py
index 75ba6e53ca0f40e8eba5222a21bcf764801c299c..b7a242d4201413064b7d3723f4938c370e2f707a 100644
--- a/tools/perf/page_sets/tough_ad_cases.py
+++ b/tools/perf/page_sets/tough_ad_cases.py
@@ -2,8 +2,11 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+from page_sets import repeatable_synthesize_scroll_gesture_shared_state
+
 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
 
 
@@ -36,9 +39,16 @@ class ScrollingPage(page_module.Page):
 
   def __init__(self, url, page_set, top_start_ratio=.5,
                make_javascript_deterministic=True):
-    super(ScrollingPage, self).__init__(url=url, page_set=page_set,
-        make_javascript_deterministic=make_javascript_deterministic)
+    super(ScrollingPage, self).__init__(
+        url=url,
+        page_set=page_set,
+        make_javascript_deterministic=make_javascript_deterministic,
+        shared_page_state_class=(
+            repeatable_synthesize_scroll_gesture_shared_state.\
+                RepeatableSynthesizeScrollGestureSharedState))
     self._top_start_ratio = top_start_ratio
+    self._scroll_multiplier = 2

[Sami, 2015/08/18 15:06:46]

Could you make this a named parameter?

[alex clarke (OOO till 29th), 2015/08/19 11:42:20]

Done.

+    print "ScrollingPage"

[Sami, 2015/08/18 15:06:46]

Probably want to leave these out :)

[alex clarke (OOO till 29th), 2015/08/19 11:42:20]

Done.

 
   def RunNavigateSteps(self, action_runner):
     # Rewrite file urls to point to the replay server instead.
@@ -59,13 +69,28 @@ class ScrollingPage(page_module.Page):
     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)
-
+    # Get the dimensions of the screen.

[Sami, 2015/08/18 15:06:46]

This is another round trip through the main thread, so should we do it as the
first thing in navigate steps instead (before we start loading the page)?

[alex clarke (OOO till 29th), 2015/08/19 11:42:20]

Done.

+    js_result = action_runner.EvaluateJavaScript(
+        'window.screen.availWidth + "," + window.screen.availHeight')
+    screensize = [int(n) for n in js_result.split(',')]
+    quarter_screen_height = screensize[1] / 4
+
+    # 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]

[Sami, 2015/08/18 15:06:46]

Could you make this into a new Action instance (with a test)?

[alex clarke (OOO till 29th), 2015/08/19 11:42:20]

Seems like a lot of boilerplate, I'm not sure I'm seeing the benefit here?

[Sami, 2015/08/19 11:54:46]

The idea was that we could use this in all page sets and not just this one. I'd
just use scroll.py as a template and remove everything that isn't needed for
this browser side scroll. In any case we need a test because otherwise this will
bitrot pretty quickly.

+    scroll_params = {
+        'x': screensize[0] / 2,
+        'y': 3 * quarter_screen_height,
+        'xDistance': 0,
+        'yDistance': -quarter_screen_height * self._scroll_multiplier,
+        'preventFling': True,
+        'repeatCount': 9,
+        'repeatDelayMs': 250,
+        'interactionMarkerName':
+            timeline_interaction_record.GetJavaScriptMarker(
+                'Gesture_ScrollAction', flags),
+    }
+    action_runner.tab.SynthesizeScrollGesture(scroll_params)

[Sami, 2015/08/18 15:06:46]

Two blank lines here please.

[alex clarke (OOO till 29th), 2015/08/19 11:42:20]

Done.

 
 class ScrollingForbesPage(ScrollingPage):
 
@@ -86,6 +111,23 @@ class ScrollingForbesPage(ScrollingPage):
     action_runner.WaitForJavaScriptCondition('document.body !== null')
 
 
+class ScrollingTmzPage(ScrollingPage):
+
+  def __init__(self, url, page_set):
+    # The TMZ page can take a while to be scrollable.
+    super(ScrollingTmzPage, self).__init__(
+        url=url, page_set=page_set, top_start_ratio=0,
+        make_javascript_deterministic=False)
+    # The TMZ page is shorter than the others.
+    self._scroll_multiplier = 1
+
+  def RunNavigateSteps(self, action_runner):
+    super(ScrollingTmzPage, self).RunNavigateSteps(action_runner)
+    # Wait for the page to be scrollable.
+    action_runner.WaitForJavaScriptCondition(
+        'document.body.scrollHeight > window.screen.height')
+
+
 class ToughAdCasesPageSet(story.StorySet):
   """Pages for measuring rendering performance with advertising content."""
 
@@ -138,6 +180,6 @@ class ScrollingToughAdCasesPageSet(story.StorySet):
     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(ScrollingTmzPage('http://m.tmz.com', self))
     self.AddStory(ScrollingPage('http://androidpolice.com', self,
         top_start_ratio=0))