Remove start & stop logic from timeline_metric.

tools/perf/measurements/thread_times.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 measurements import timeline_controller
 from metrics import timeline
 from telemetry.page import page_measurement
 
 class ThreadTimes(page_measurement.PageMeasurement):
   def __init__(self):
     super(ThreadTimes, self).__init__('RunSmoothness')
-    self._metric = None
+    self._timeline_controller = None
 
   @classmethod
   def AddCommandLineArgs(cls, parser):
     parser.add_option('--report-silk-results', action='store_true',
                       help='Report results relevant to silk.')
     parser.add_option('--report-silk-details', action='store_true',
                       help='Report details relevant to silk.')
 
   @property
   def results_are_the_same_on_every_page(self):
     return False
 
   def WillRunActions(self, page, tab):
-    self._metric = timeline.ThreadTimesTimelineMetric()
-    if self.options.report_silk_results:
-      self._metric.results_to_report = timeline.ReportSilkResults
+    self._timeline_controller = timeline_controller.TimelineController()
     if self.options.report_silk_details:
-      self._metric.details_to_report = timeline.ReportSilkDetails
-    self._metric.Start(page, tab)
+      # We need the other traces in order to have any details to report.
+      self.timeline_controller.trace_categories = \
+          timeline_controller.DEFAULT_TRACE_CATEGORIES
+    else:
+      self._timeline_controller.trace_categories = \
+          timeline_controller.MINIMAL_TRACE_CATEGORIES
+    self._timeline_controller.Start(page, tab)
 
   def DidRunAction(self, page, tab, action):
-    self._metric.AddActionToIncludeInMetric(action)
+    self._timeline_controller.AddActionToIncludeInMetric(action)
 
   def DidRunActions(self, page, tab):
-    self._metric.Stop(page, tab)
+    self._timeline_controller.Stop(tab)
 
   def MeasurePage(self, page, tab, results):
-    self._metric.AddResults(tab, results)
+    metric = timeline.ThreadTimesTimelineMetric(
+      self._timeline_controller.model,
+      self._timeline_controller.renderer_process,
+      self._timeline_controller.action_ranges)
+    if self.options.report_silk_results:
+      metric.results_to_report = timeline.ReportSilkResults
+    if self.options.report_silk_details:
+      metric.details_to_report = timeline.ReportSilkDetails
+    metric.AddResults(tab, results)