Convert smoothness to the new timeline based metric API.

tools/perf/metrics/timeline.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.
 import collections
 import itertools
 
 from metrics import Metric
 from telemetry.core.timeline.model import TimelineModel
 from telemetry.core.timeline import bounds
 from telemetry.page import page_measurement
@@ skipping 33 matching lines @@
 
   def Start(self, page, tab):
     """Starts gathering timeline data.
 
     mode: TRACING_MODE or TIMELINE_MODE
     """
     self._model = None
     if self._mode == TRACING_MODE:
       if not tab.browser.supports_tracing:
         raise Exception('Not supported')
-      tab.browser.StartTracing(self.trace_categories)
+      if self.trace_categories:
+        categories = [self.trace_categories] + \
+            page.GetSyntheticDelayCategories()
+      else:
+        categories = page.GetSyntheticDelayCategories()
+      tab.browser.StartTracing(','.join(categories))
     else:
       assert self._mode == TIMELINE_MODE
       tab.StartTimelineRecording()
 
   def Stop(self, page, tab):
     if self._mode == TRACING_MODE:
       timeline_data = tab.browser.StopTracing()
       self._model = TimelineModel(timeline_data)
       self._renderer_process = self._model.GetRendererProcessFromTab(tab)
       self._action_ranges = [ action.GetActiveRangeOnTimeline(self._model)
@@ skipping 273 matching lines @@
     num_frames = self.CountSlices(frame_slices, FrameTraceName)
 
     # Report the desired results and details.
     for thread_results in thread_category_results.values():
       if thread_results.name in self.results_to_report:
         thread_results.AddResults(num_frames, results)
       # TOOD(nduca): When generic results objects are done, this special case
       # can be replaced with a generic UI feature.
       if thread_results.name in self.details_to_report:
         thread_results.AddDetailedResults(num_frames, results)