Adding dumpsys based power monitor for android.

tools/telemetry/telemetry/core/platform/power_monitor/__init__.py

Index: tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
diff --git a/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py b/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
index 4aee1c247662ea5a0a12a32ccaba3d0c38cea638..4d98e075d6057a56a331b01934d6437961f1ac22 100644
--- a/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
+++ b/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
@@ -10,19 +10,22 @@ class PowerMonitor(object):
 
   Provides an interface to register power consumption during a test.
   """
-  def CanMonitorPowerAsync(self):
+  def CanMonitorPower(self):
     """Returns True iff power can be monitored asynchronously via
-    StartMonitoringPowerAsync() and StopMonitoringPowerAsync().
+    StartMonitoringPower() and StopMonitoringPower().
     """
     return False
 
-  def StartMonitoringPowerAsync(self):
-    """Starts monitoring power utilization statistics."""
+  def StartMonitoringPower(self, browser):
+    """Starts monitoring power utilization statistics.
+
+    See Platform#StartMonitoringPower for the arguments format.
+    """
     raise NotImplementedError()
 
-  def StopMonitoringPowerAsync(self):
+  def StopMonitoringPower(self):
     """Stops monitoring power utilization and returns collects stats
 
-    See Platform#StopMonitoringPowerAsync for the return format.
+    See Platform#StopMonitoringPower for the return format.
     """
     raise NotImplementedError()