Add a telemetry measurement for property tree performance.

tools/perf/benchmarks/draw_properties.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 import benchmark
+
+from measurements import draw_properties
+import page_sets
+
+
+class DrawPropertiesToughScrolling(benchmark.Benchmark):
+  test = draw_properties.DrawProperties
+  page_set = page_sets.ToughScrollingCasesPageSet
+  @classmethod
+  def Name(cls):
+    return 'draw_properties.tough_scrolling'
+
+class DrawPropertiesTop25(benchmark.Benchmark):
+  """Measures rendering statistics while scrolling down the top 25 web pages.

[sullivan, 2015/02/26 21:59:02]

Is this actually meant to scroll? I don't see any code that scrolls anywhere.

[Ian Vollick, 2015/02/26 22:59:39]

I'm honestly not sure the mechanism by which scrolling is specified, but this
certainly does cause scrolling in my tests. Perhaps the interaction is baked
into the page set?

[sullivan, 2015/02/28 15:58:05]

Oops, yeah, it's coded into the page interactions of both pagesets.

FYI, the class-level comment you put here and above gets uploaded to the perf
dashboard as the benchmark documentation. So please double-check that it's what
you'd like the people viewing graphs to see!

[Ian Vollick, 2015/02/28 22:22:14]

Yeah, my comment was pretty crummy. Updated.

+
+  http://www.chromium.org/developers/design-documents/rendering-benchmarks
+  """
+  test = draw_properties.DrawProperties
+  page_set = page_sets.Top25SmoothPageSet
+
+  @classmethod
+  def Name(cls):
+    return 'draw_properties.top_25'