Add a telemetry measurement for property tree performance.

tools/perf/measurements/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.core.platform import tracing_category_filter
+from telemetry.core.platform import tracing_options
+from telemetry.page import page_test
+from telemetry.timeline import model
+from telemetry.value import scalar
+
+
+class DrawProperties(page_test.PageTest):
+  def __init__(self):
+    super(DrawProperties, self).__init__(
+      action_name_to_run='RunPageInteractions')
+
+  def CustomizeBrowserOptions(self, options):
+    options.AppendExtraBrowserArgs('--enable-property-tree-verification')
+
+  def WillNavigateToPage(self, page, tab):
+    options = tracing_options.TracingOptions()
+    options.enable_chrome_trace = True
+    category_filter = tracing_category_filter.TracingCategoryFilter(
+        'disabled-by-default-cc.debug.cdp-perf')
+    tab.browser.platform.tracing_controller.Start(options, category_filter)
+
+  def ValidateAndMeasurePage(self, page, tab, results):
+    timeline_data = tab.browser.platform.tracing_controller.Stop()
+    timeline_model = model.TimelineModel(timeline_data)
+
+    def _IsDone():
+      return tab.EvaluateJavaScript('isDone')
+
+    cdp_events = timeline_model.GetAllEventsOfName(
+        "LayerTreeHostCommon::CalculateDrawProperties");
+
+    durations = [d.duration for d in cdp_events]
+    assert durations, 'Failed to find cdp durations'
+
+    cdp_sum = sum(durations)
+
+    pt_events = timeline_model.GetAllEventsOfName(
+        "LayerTreeHostCommon::ComputeVisibleRectsWithPropertyTrees");
+
+    durations = [d.duration for d in pt_events]
+    assert durations, 'Failed to find pt durations'
+
+    pt_sum = sum(durations)
+
+    reduction = 100.0 * (1.0 - (pt_sum / cdp_sum))
+
+    results.AddValue(scalar.ScalarValue(
+        results.current_page, 'CDP_reduction', 'percent', reduction,
+        description='Reduction in CDP cost with property trees'))
+
+  def CleanUpAfterPage(self, page, tab):
+    tracing_controller = tab.browser.platform.tracing_controller
+    if tracing_controller.is_tracing_running:
+      tracing_controller.Stop()