[Telemetry] Add power usage metric

tools/perf/measurements/smoothness.py

Index: tools/perf/measurements/smoothness.py
diff --git a/tools/perf/measurements/smoothness.py b/tools/perf/measurements/smoothness.py
index 4715afac63810d36cb01a3f8dc83d7c557498305..a84a4acb29204c70fc9cc0627727bbbbafb73f5d 100644
--- a/tools/perf/measurements/smoothness.py
+++ b/tools/perf/measurements/smoothness.py
@@ -2,29 +2,37 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+from metrics import power
 from metrics import smoothness
 from telemetry.page import page_measurement
 
+
 class Smoothness(page_measurement.PageMeasurement):
   def __init__(self):
     super(Smoothness, self).__init__('smoothness')
-    self._metric = None
+    self._smoothness_metric = None
+    self._power_metric = None
 
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')
+    power.PowerMetric.CustomizeBrowserOptions(options)
 
   def CanRunForPage(self, page):
     return hasattr(page, 'smoothness')
 
   def WillRunActions(self, page, tab):
-    self._metric = smoothness.SmoothnessMetric()
-    self._metric.Start(page, tab)
+    self._power_metric = power.PowerMetric()
+    self._power_metric.Start(page, tab)
+    self._smoothness_metric = smoothness.SmoothnessMetric()
+    self._smoothness_metric.Start(page, tab)
 
   def DidRunAction(self, page, tab, action):
-    self._metric.AddActionToIncludeInMetric(action)
+    self._smoothness_metric.AddActionToIncludeInMetric(action)
 
   def DidRunActions(self, page, tab):
-    self._metric.Stop(page, tab)
+    self._power_metric.Stop(page, tab)
+    self._smoothness_metric.Stop(page, tab)
 
   def MeasurePage(self, page, tab, results):
-    self._metric.AddResults(tab, results)
+    self._power_metric.AddResults(tab, results)
+    self._smoothness_metric.AddResults(tab, results)