[Telemetry] Add power usage metric

tools/perf/measurements/startup.py

Index: tools/perf/measurements/startup.py
diff --git a/tools/perf/measurements/startup.py b/tools/perf/measurements/startup.py
index c9bb6b30a9dacc39e1ca465e70648b3ba982e60c..8831327381c53af68eb1901f56892cb4b1aef018 100644
--- a/tools/perf/measurements/startup.py
+++ b/tools/perf/measurements/startup.py
@@ -2,6 +2,7 @@
 # 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 startup_metric
 from telemetry.page import page_measurement
 
@@ -17,6 +18,7 @@ class Startup(page_measurement.PageMeasurement):
   def __init__(self, action_name_to_run = ''):
     super(Startup, self).__init__(needs_browser_restart_after_each_run=True,
                                   action_name_to_run=action_name_to_run)
+    self._power_metric = None

[tonyg, 2014/01/23 18:23:40]

startup represents such a fleeting period that it isn't clear to me whether
there is value in measuring our efficiency during startup.

I suggested some metrics which I do think benefit from power measurement here:
https://code.google.com/p/chromium/issues/detail?id=336672

But perhaps we want to use the metric in a follow-up CL just in case something
breaks, then we don't have to worry about reverting the Metric itself.

[jeremy, 2014/01/23 18:58:41]

Done.

 
   def AddCommandLineOptions(self, parser):
     parser.add_option('--cold', action='store_true',
@@ -43,7 +45,13 @@ class Startup(page_measurement.PageMeasurement):
     # Overriden so that no page navigation occurs - startup to the NTP.
     pass
 
+  def WillStartBrowser(self, browser):
+    self._power_metric = power.PowerMetric()
+    self._power_metric.Start(None, None)
+
   def MeasurePage(self, page, tab, results):
+    self._power_metric.Stop(None, None)
+    self._power_metric.AddResults(tab, results)
     startup_metric.StartupMetric().AddResults(tab, results)
 
 
@@ -60,4 +68,4 @@ class StartWithUrl(Startup):
   """
 
   def __init__(self):
-    super(StartWithUrl, self).__init__(action_name_to_run='navigate_steps')
+    super(StartWithUrl, self).__init__(action_name_to_run='navigate_steps')