tools: Add tough_fast_scrolling_cases page set.

tools/perf/page_sets/tough_fast_scrolling_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 ToughFastScrollingCasesPage(page_module.Page):
+
+  def __init__(self, url, page_set):
+    super(ToughFastScrollingCasesPage, self).__init__(
+      url=url,
+      page_set=page_set)
+
+  def RunSmoothness(self, action_runner):
+    interaction = action_runner.BeginGestureInteraction(
+        'ScrollAction', is_smooth=True)
+    action_runner.ScrollPage(direction='down', speed_in_pixels_per_second=16000)
+    interaction.End()
+
+
+class ToughFastScrollingCasesPageSet(page_set_module.PageSet):
+
+  """
+  Description: A collection of difficult fast scrolling tests
+  """
+
+  def __init__(self):
+    super(ToughFastScrollingCasesPageSet, self).__init__()
+
+    urls_list = [
+      'file://tough_fast_scrolling_cases/lorem_ipsum.html',
+      'file://tough_fast_scrolling_cases/canvas.html',
+    ]
+
+    for url in urls_list:
+      self.AddPage(ToughFastScrollingCasesPage(url, self))