Add GetThreadToInteractionRecordsMapsFromModel method to timeline_interaction_record.

tools/telemetry/telemetry/web_perf/timeline_based_measurement.py

Index: tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
diff --git a/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py b/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
index 2b093a7b0f48b365caa2ca2f178fc880911d4d65..0e35d33e01dbb0025ec9e3c6dee38f4bf70bd524 100644
--- a/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
+++ b/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
@@ -65,18 +65,20 @@ class _ResultsWrapper(object):
     self._results.AddValue(value)
 
 class _TimelineBasedMetrics(object):
-  def __init__(self, model, renderer_thread,
-               get_metric_from_metric_type_callback):
+  def __init__(self, model, get_metric_from_metric_type_callback):
     self._model = model
-    self._renderer_thread = renderer_thread
     self._get_metric_from_metric_type_callback = \
         get_metric_from_metric_type_callback
 
   def FindTimelineInteractionRecords(self):
     # TODO(nduca): Add support for page-load interaction record.
-    return [tir_module.TimelineInteractionRecord.FromAsyncEvent(event) for
-            event in self._renderer_thread.async_slices
-            if tir_module.IsTimelineInteractionRecord(event.name)]
+    threads_to_records_map = (
+        tir_module.GetThreadToInteractionRecordsMapsFromModel(self._model))
+    #TODO(nednguyen) support multiple records on multiple threads
+    assert len(threads_to_records_map) == 1, (
+        'TimelineBasedMeasurement only support interaction records issued'
+        ' from a single thread.')
+    return threads_to_records_map.values[0]
 
   def AddResults(self, results):
     all_interactions = self.FindTimelineInteractionRecords()
@@ -108,8 +110,7 @@ class _TimelineBasedMetrics(object):
         raise InvalidInteractions('Interaction records with the same logical '
                                   'name must have the same flags.')
       metric = self._get_metric_from_metric_type_callback(metric_type)
-      metric.AddResults(self._model, self._renderer_thread,
-                        interactions, wrapped_results)
+      metric.AddResults(self._model, interactions, wrapped_results)
 
 
 class TimelineBasedMeasurement(page_measurement.PageMeasurement):
@@ -180,9 +181,7 @@ class TimelineBasedMeasurement(page_measurement.PageMeasurement):
         logging.error('Cannot open %s. %s' % (trace_file_path, e))
 
     model = model_module.TimelineModel(trace_result)
-    renderer_thread = model.GetRendererThreadFromTabId(tab.id)
-    meta_metrics = _TimelineBasedMetrics(
-        model, renderer_thread, _GetMetricFromMetricType)
+    meta_metrics = _TimelineBasedMetrics(model, _GetMetricFromMetricType)
     meta_metrics.AddResults(results)
 
   def CleanUpAfterPage(self, page, tab):