[Android] Force enable battery updates instead of resetting to clear power data.

build/android/pylib/device/battery_utils.py

Index: build/android/pylib/device/battery_utils.py
diff --git a/build/android/pylib/device/battery_utils.py b/build/android/pylib/device/battery_utils.py
index ed66591daa5c6ac2df287ffaca938020d47fa37e..2eab9f2fc4476e989b174a680e52e6881c1760d5 100644
--- a/build/android/pylib/device/battery_utils.py
+++ b/build/android/pylib/device/battery_utils.py
@@ -289,7 +289,9 @@ class BatteryUtils(object):
       raise device_errors.DeviceVersionError('Device must be L or higher.')
 
     self._device.RunShellCommand(
-        ['dumpsys', 'battery', 'reset'], check_return=True)

[jbudorick, 2015/06/09 18:29:16]

Is there anything covered by reset that isn't covered by set usb 1 and set ac 1?

[rnephew (Reviews Here), 2015/06/09 19:07:29]

The only purpose of the reset here is to make sure the phone was aware it was
charging, so that when you run the batterystats --reset command it will not
start adding new power right away and fail the 'did power reset' check. When
using adb over wifi, resetting just leaves it in a state where its not charging
so the 'did power reset' check fails since as soon as it is cleared, it starts
adding new measurements. 

The battery reset in EnableBatteryUpdates is the important one, since it is for
actually resetting the battery state. 

[jbudorick, 2015/06/09 19:09:45]

I take it that the dumpsys battery reset in EnableBatteryUpdates will work on
wifi?

+        ['dumpsys', 'battery', 'set', 'usb', '1'], check_return=True)
+    self._device.RunShellCommand(
+        ['dumpsys', 'battery', 'set', 'ac', '1'], check_return=True)
     self._device.RunShellCommand(
         ['dumpsys', 'batterystats', '--reset'], check_return=True)
     battery_data = self._device.RunShellCommand(