Add responsiveness_metric for timeline_based_measurement

tools/telemetry/telemetry/core/timeline/thread.py

Index: tools/telemetry/telemetry/core/timeline/thread.py
diff --git a/tools/telemetry/telemetry/core/timeline/thread.py b/tools/telemetry/telemetry/core/timeline/thread.py
index 3b76397ed8bd97fee1619f70cb2c51d8d89c7b74..f0762c8e202ab61a31c2ddf24fa96df8a38be2a9 100644
--- a/tools/telemetry/telemetry/core/timeline/thread.py
+++ b/tools/telemetry/telemetry/core/timeline/thread.py
@@ -54,11 +54,23 @@ class Thread(event_container.TimelineEventContainer):
       for sub_slice in s.IterEventsInThisContainerRecrusively():
         yield sub_slice
 
-  def IterAllSlicesInRange(self, start, end):
+  def IterAllSlicesInTimeRange(self, start, end):
+    """ Returns all slices with time ranges within start and end, inclusive. """
     for s in self.IterAllSlices():
       if s.start >= start and s.end <= end:
         yield s
 
+  def IterAllSlicesOverlappedWithThreadTimeRange(self, thread_start,
+                                                 thread_end):
+    """ Returns all slices whose thread time ranges overlap with the range
+        (thread_start, thread_end).
+    """
+    for s in self.IterAllSlices():
+
+      if (s.HasThreadTimeData() and s.thread_end > thread_start and
+          s.thread_start < thread_end):
+        yield s
+
   def IterAllSlicesOfName(self, name):
     for s in self.IterAllSlices():
       if s.name == name: