[PCv2] Add tracing category needed for computing ttfmp

tools/perf/benchmarks/page_cycler_v2.py

 # Copyright 2016 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.
 
 """The page cycler v2.
 
 For details, see design doc:
 https://docs.google.com/document/d/1EZQX-x3eEphXupiX-Hq7T4Afju5_sIdxPWYetj7ynd0
 """
 
 from core import perf_benchmark
 import page_sets
 
 from telemetry import benchmark
 from telemetry.page import cache_temperature
 from telemetry.timeline import tracing_category_filter
 from telemetry.web_perf import timeline_based_measurement
 
 
 class _PageCyclerV2(perf_benchmark.PerfBenchmark):
   def CreateTimelineBasedMeasurementOptions(self):
     cat_filter = tracing_category_filter.TracingCategoryFilter(
         filter_string='*,blink.console,navigation,blink.user_timing,loading')
 
+    # Needed for first-meaningful-paint computation.
+    cat_filter.AddIncludedCategory('disabled-by-default-blink.debug.layout')

[Kunihiko Sakamoto, 2016/06/08 01:56:50]

We also need devtools.timeline category for the paint events.

[kouhei (in TOK), 2016/06/08 01:59:07]

Done.

+
     tbm_options = timeline_based_measurement.Options(
         overhead_level=cat_filter)
     tbm_options.SetTimelineBasedMetric('firstPaintMetric')
     return tbm_options
 
 
 @benchmark.Disabled('win')  # crbug.com/615178
 class PageCyclerV2Typical25(_PageCyclerV2):
   """Page load time benchmark for a 25 typical web pages.
 
@@ skipping 10 matching lines @@
   def ShouldDisable(cls, possible_browser):  # crbug.com/615178
     return ((possible_browser.browser_type == 'reference' and
              possible_browser.platform.GetOSName() == 'android') or
             cls.IsSvelte(possible_browser) or  # crbug.com/616781
             possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X')
 
   def CreateStorySet(self, options):
     return page_sets.Typical25PageSet(run_no_page_interactions=True,
         cache_temperatures=[
           cache_temperature.PCV1_COLD, cache_temperature.PCV1_WARM])