Add some statistics to the monsoon profile run

tools/perf/metrics/smoothness.py

Index: tools/perf/metrics/smoothness.py
diff --git a/tools/perf/metrics/smoothness.py b/tools/perf/metrics/smoothness.py
index 4041900847f315f1e93df7bd235774371028c167..d638da917e3f2ed2250b8503b63671347404e407 100644
--- a/tools/perf/metrics/smoothness.py
+++ b/tools/perf/metrics/smoothness.py
@@ -4,10 +4,10 @@
 
 from metrics import Metric
 from metrics import rendering_stats
-from metrics import statistics
 from telemetry.page import page_measurement
 from telemetry.page.perf_tests_helper import FlattenList
 from telemetry.core.timeline.model import TimelineModel
+from telemetry.util import statistics
 
 TIMELINE_MARKER = 'Smoothness'
 
@@ -76,8 +76,7 @@ class SmoothnessMetric(Metric):
   def AddResults(self, tab, results):
     if self._stats.mouse_wheel_scroll_latency:
       mean_mouse_wheel_scroll_latency = statistics.ArithmeticMean(
-          self._stats.mouse_wheel_scroll_latency,
-          len(self._stats.mouse_wheel_scroll_latency))
+          self._stats.mouse_wheel_scroll_latency)
       mouse_wheel_scroll_latency_discrepancy = statistics.DurationsDiscrepancy(
           self._stats.mouse_wheel_scroll_latency)
       results.Add('mean_mouse_wheel_scroll_latency', 'ms',
@@ -87,8 +86,7 @@ class SmoothnessMetric(Metric):
 
     if self._stats.touch_scroll_latency:
       mean_touch_scroll_latency = statistics.ArithmeticMean(
-          self._stats.touch_scroll_latency,
-          len(self._stats.touch_scroll_latency))
+          self._stats.touch_scroll_latency)
       touch_scroll_latency_discrepancy = statistics.DurationsDiscrepancy(
           self._stats.touch_scroll_latency)
       results.Add('mean_touch_scroll_latency', 'ms',
@@ -98,8 +96,7 @@ class SmoothnessMetric(Metric):
 
     if self._stats.js_touch_scroll_latency:
       mean_js_touch_scroll_latency = statistics.ArithmeticMean(
-          self._stats.js_touch_scroll_latency,
-          len(self._stats.js_touch_scroll_latency))
+          self._stats.js_touch_scroll_latency)
       js_touch_scroll_latency_discrepancy = statistics.DurationsDiscrepancy(
           self._stats.js_touch_scroll_latency)
       results.Add('mean_js_touch_scroll_latency', 'ms',
@@ -112,8 +109,7 @@ class SmoothnessMetric(Metric):
     results.Add('frame_times', 'ms', frame_times)
 
     # Arithmetic mean of frame times.
-    mean_frame_time = statistics.ArithmeticMean(frame_times,
-                                                len(frame_times))
+    mean_frame_time = statistics.ArithmeticMean(frame_times)
     results.Add('mean_frame_time', 'ms', round(mean_frame_time, 3))
 
     # Absolute discrepancy of frame time stamps.