Collecting LatencyInfo in telemetry

tools/perf/measurements/smoothness_unittest.py

Index: tools/perf/measurements/smoothness_unittest.py
diff --git a/tools/perf/measurements/smoothness_unittest.py b/tools/perf/measurements/smoothness_unittest.py
index 4404393aba45fd67a8515fa542b5d16797ab162f..424ab5c029a2645e4f7a737429511ead5ebd9767 100644
--- a/tools/perf/measurements/smoothness_unittest.py
+++ b/tools/perf/measurements/smoothness_unittest.py
@@ -40,3 +40,24 @@ class SmoothnessUnitTest(
     mostly_smooth = results.FindAllPageSpecificValuesNamed('mostly_smooth')
     self.assertEquals(len(mostly_smooth), 1)
     self.assertGreaterEqual(mostly_smooth[0].GetRepresentativeNumber(), 0)
+
+    mean_mouse_wheel_latency = results.FindAllPageSpecificValuesNamed(
+        'mean_mouse_wheel_latency')
+    if mean_mouse_wheel_latency:
+      self.assertEquals(len(mean_mouse_wheel_latency), 1)
+      self.assertGreater(
+          mean_mouse_wheel_latency[0].GetRepresentativeNumber(), 0)
+
+    mean_gesture_scroll_latency = results.FindAllPageSpecificValuesNamed(
+        'mean_gesture_scroll_latency')
+    if mean_gesture_scroll_latency:
+      self.assertEquals(len(mean_gesture_scroll_latency), 1)
+      self.assertGreater(
+          mean_gesture_scroll_latency[0].GetRepresentativeNumber(), 0)
+
+    mean_touch_scroll_latency = results.FindAllPageSpecificValuesNamed(
+        'mean_touch_scroll_latency')
+    if mean_touch_scroll_latency:
+      self.assertEquals(len(mean_touch_scroll_latency), 1)
+      self.assertGreater(
+          mean_touch_scroll_latency[0].GetRepresentativeNumber(), 0)