Adding dumpsys based power monitor for android.

tools/perf/metrics/power.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import logging
 
 from metrics import Metric
 from telemetry.core.platform import factory
 
 
@@ skipping 16 matching lines @@
     parent = super(PowerMetric, self)
     if hasattr(parent, '__del__'):
       parent.__del__()
 
   def _StopInternal(self):
     """ Stop monitoring power if measurement is running. This function is
     idempotent."""
     if not self._running:
       return
     self._running = False
-    self._results = self._browser.platform.StopMonitoringPowerAsync()
-    if self._results: # StopMonitoringPowerAsync() can return None.
+    self._results = self._browser.platform.StopMonitoringPower()
+    if self._results: # StopMonitoringPower() can return None.
       self._results['cpu_stats'] = (
           _SubtractCpuStats(self._browser.cpu_stats, self._starting_cpu_stats))
 
   @classmethod
   def CustomizeBrowserOptions(cls, options):
     PowerMetric.enabled = options.report_root_metrics
 
     # Friendly informational messages if measurement won't run.
     system_supports_power_monitoring = (
-        factory.GetPlatformBackendForCurrentOS().CanMonitorPowerAsync())
+        factory.GetPlatformBackendForCurrentOS().CanMonitorPower())
     if system_supports_power_monitoring:
       if not PowerMetric.enabled:
         logging.warning(
             "--report-root-metrics omitted, power measurement disabled.")
     else:
       logging.info("System doesn't support power monitoring, power measurement"
           " disabled.")
 
   def Start(self, _, tab):
     if not PowerMetric.enabled:
       return
 
-    if not tab.browser.platform.CanMonitorPowerAsync():
+    if not tab.browser.platform.CanMonitorPower():
       return
 
     self._results = None
     self._browser = tab.browser
     self._StopInternal()
 
     # This line invokes top a few times, call before starting power measurement.
     self._starting_cpu_stats = self._browser.cpu_stats
-    self._browser.platform.StartMonitoringPowerAsync()
+    self._browser.platform.StartMonitoringPower(self._browser)
     self._running = True
 
   def Stop(self, _, tab):
     if not PowerMetric.enabled:
       return
 
-    if not tab.browser.platform.CanMonitorPowerAsync():
+    if not tab.browser.platform.CanMonitorPower():
       return
 
     self._StopInternal()
 
   def AddResults(self, _, results):
     if not self._results:
       return
 
     energy_consumption_mwh = self._results['energy_consumption_mwh']
     results.Add('energy_consumption_mwh', 'mWh', energy_consumption_mwh)
@@ skipping 15 matching lines @@
   Returns:
     A dict of process type names (Browser, Renderer, etc.) to idle wakeup count
     over the period recorded by the input.
   """
   cpu_delta = {}
   for process_type in cpu_stats:
     assert process_type in start_cpu_stats, 'Mismatching process types'
     # Skip any process_types that are empty.
     if (not cpu_stats[process_type]) or (not start_cpu_stats[process_type]):
       continue
+    # Skip if IdleWakeupCount is not present.
+    if (('IdleWakeupCount' not in cpu_stats[process_type]) or
+        ('IdleWakeupCount' not in start_cpu_stats[process_type])):
+      continue
     idle_wakeup_delta = (cpu_stats[process_type]['IdleWakeupCount'] -
                         start_cpu_stats[process_type]['IdleWakeupCount'])
     cpu_delta[process_type] = idle_wakeup_delta
   return cpu_delta