smoothness.scrolling_tough_ad_cases to use browser driven scrolls

tools/telemetry/telemetry/internal/actions/repeatable_scroll.py

Index: tools/telemetry/telemetry/internal/actions/repeatable_scroll.py
diff --git a/tools/telemetry/telemetry/internal/actions/repeatable_scroll.py b/tools/telemetry/telemetry/internal/actions/repeatable_scroll.py
new file mode 100644
index 0000000000000000000000000000000000000000..ef33399d3e41b132645bd625718b38f399a7bfdc
--- /dev/null
+++ b/tools/telemetry/telemetry/internal/actions/repeatable_scroll.py
@@ -0,0 +1,38 @@
+# 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.internal.actions import page_action
+from telemetry.web_perf import timeline_interaction_record
+
+
+class RepeatableScrollAction(page_action.PageAction):
+
+  def __init__(self, x_scroll_distance_ratio=0.0, y_scroll_distance_ratio=0.5,
+               repeat_count=0, repeat_delay_ms=250):
+    super(RepeatableScrollAction, self).__init__()
+    self._x_scroll_distance_ratio = x_scroll_distance_ratio
+    self._y_scroll_distance_ratio = y_scroll_distance_ratio
+    self._repeat_count = repeat_count
+    self._repeat_delay_ms = repeat_delay_ms
+    self._windowsize = []
+
+  def WillRunAction(self, tab):
+    # Get the dimensions of the screen.
+    window_info_js = 'window.innerWidth + "," + window.innerHeight'
+    js_result = tab.EvaluateJavaScript(window_info_js).split(',')
+
+    self._windowsize = [int(js_result[0]), int(js_result[1])]
+
+  def RunAction(self, tab):
+    # Set up a browser driven repeating scroll. The delay between the scrolls
+    # should be unaffected by render thread responsivness (or lack there of).
+    tab.SynthesizeScrollGesture(
+        x=int(self._windowsize[0] / 2),
+        y=int(self._windowsize[1] / 2),
+        xDistance=int(self._x_scroll_distance_ratio * self._windowsize[0]),
+        yDistance=int(-self._y_scroll_distance_ratio * self._windowsize[1]),
+        repeatCount=self._repeat_count,
+        repeatDelayMs=self._repeat_delay_ms,
+        interactionMarkerName=timeline_interaction_record.GetJavaScriptMarker(
+            'Gesture_ScrollAction', [timeline_interaction_record.REPEATABLE]))