Add new method to disable android device charging.

build/android/pylib/device/device_utils_test.py

Index: build/android/pylib/device/device_utils_test.py
diff --git a/build/android/pylib/device/device_utils_test.py b/build/android/pylib/device/device_utils_test.py
index b7e807e06d74cf063d247e10b99c93fe870b4b5c..46fae0405780b49683c2a8488d4da17894f7bdf1 100755
--- a/build/android/pylib/device/device_utils_test.py
+++ b/build/android/pylib/device/device_utils_test.py
@@ -1468,6 +1468,22 @@ class DeviceUtilsSetChargingTest(DeviceUtilsTest):
       self.device.SetCharging(False)
 
 
+class DeviceUtilsSetBatteryMeasurementTest(DeviceUtilsTest):
+
+  def testBatteryMeasurement(self):
+    with self.assertCalls(
+        (self.call.device.RunShellCommand(
+            mock.ANY, retries=0, single_line=True,

[perezju, 2015/03/13 10:19:07]

I'm never quite sure what is the "right" level of abstraction for these tests;
but maybe we could change some of these mock.ANY's to the actual commands?

[rnephew (Wrong account), 2015/03/16 16:33:40]

Done.

+            timeout=10, check_return=True), '22'),
+        (self.call.device.RunShellCommand(mock.ANY, check_return=True), []),
+        (self.call.device.RunShellCommand(mock.ANY, check_return=True), []),
+        (self.call.device.RunShellCommand(mock.ANY, check_return=True), []),
+        (self.call.device.GetCharging(), False),
+        (self.call.device.RunShellCommand(mock.ANY, check_return=True), []),
+        (self.call.device.GetCharging(), True)):
+      with self.device.BatteryMeasurement():
+        pass
+
 
 class DeviceUtilsStrTest(DeviceUtilsTest):