Refactoring scrolling_benchmark code into scrolling_interaction.py

tools/telemetry/telemetry/scrolling_interaction.py

Index: tools/telemetry/telemetry/scrolling_interaction.py
diff --git a/tools/telemetry/telemetry/scrolling_interaction.py b/tools/telemetry/telemetry/scrolling_interaction.py
new file mode 100644
index 0000000000000000000000000000000000000000..a404fb3c6647af61433eed212dc5ced75657f288
--- /dev/null
+++ b/tools/telemetry/telemetry/scrolling_interaction.py
@@ -0,0 +1,43 @@
+# Copyright (c) 2012 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.
+import os
+
+from telemetry import page_interaction
+from telemetry import util
+
+class ScrollingInteraction(page_interaction.PageInteraction):
+  def __init__(self, attributes=None):
+    super(ScrollingInteraction, self).__init__(attributes)
+
+  def PerformInteraction(self, page, tab):
+    scroll_js_path = os.path.join(os.path.dirname(__file__), 'scroll.js')
+    scroll_js = open(scroll_js_path, 'r').read()
+
+    # Run scroll test.
+    tab.runtime.Execute(scroll_js)
+
+    with tab.browser.platform.GetSurfaceCollector(''):
+
+      start_scroll_js = """
+        window.__renderingStatsDeltas = null;
+        new __ScrollTest(function(rendering_stats_deltas) {
+          window.__renderingStatsDeltas = rendering_stats_deltas;
+        }).start(element);
+      """
+      # scrollable_element_function is a function that passes the scrollable
+      # element on the page to a callback. For example:
+      #   function (callback) {
+      #     callback(document.getElementById('foo'));
+      #   }
+      if hasattr(self, 'scrollable_element_function'):
+        tab.runtime.Execute('(%s)(function(element) { %s });' %
+                            (self.scrollable_element_function, start_scroll_js))
+      else:
+        tab.runtime.Execute(
+            '(function() { var element = document.body; %s})();' %
+            start_scroll_js)
+
+      # Poll for scroll benchmark completion.
+      util.WaitFor(lambda: tab.runtime.Evaluate(
+          'window.__renderingStatsDeltas'), 60)