Add GetThreadToInteractionRecordsMapsFromModel method to timeline_interaction_record.

tools/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py

Index: tools/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py
diff --git a/tools/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py b/tools/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py
index f406b12c1403169a175c9b550506c219cb5c6f00..38f11518c69d594f2447bd195a232133d78d09b9 100644
--- a/tools/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py
+++ b/tools/telemetry/telemetry/web_perf/metrics/timeline_based_metric.py
@@ -34,7 +34,7 @@ class TimelineBasedMetric(object):
     """
     super(TimelineBasedMetric, self).__init__()
 
-  def AddResults(self, model, renderer_thread, interaction_records, results):
+  def AddResults(self, model, interaction_records, results):
     """Computes and adds metrics for the interaction_records' time ranges.
 
     The override of this method should compute results on the data **only**
@@ -51,9 +51,23 @@ class TimelineBasedMetric(object):
     raise NotImplementedError()
 
   def VerifyNonOverlappedRecords(self, interaction_records):
-    """This raises exceptions if interaction_records contain overlapped ranges.
+    """This raises exception if interaction_records contain overlapped ranges.
     """
     if _TimeRangesHasOverlap(((r.start, r.end) for r in interaction_records)):
       raise TimelineBasedMetricException(
           'This metric does not support interaction records with overlapped '
           'time range.')
+
+  def VerifyAllRecordsIssuedBySameThread(self, interaction_records):
+    """This raises exception if interaction records are not issued by the same
+    thread.
+    """
+    assert interaction_records[0].async_event
+    first_record_start_thread = interaction_records[0].async_event.start_thread
+    assert first_record_start_thread
+    for r in interaction_records:
+      if (r.async_event.start_thread is not first_record_start_thread or
+          r.async_event.end_thread is not first_record_start_thread):
+        raise TimelineBasedMetricException(
+            'This metric does not support interaction records that are not '
+            'issued by a same thread.')