[Android] Detect if device is not charging properly.

build/android/devil/android/device_errors.py

Index: build/android/devil/android/device_errors.py
diff --git a/build/android/devil/android/device_errors.py b/build/android/devil/android/device_errors.py
index ea14bf9ad8b9a7d144ce70fc4cd3559b0541c7b7..c27d96321ae26b9c2a5bc4d8551f4fb3a93806c1 100644
--- a/build/android/devil/android/device_errors.py
+++ b/build/android/devil/android/device_errors.py
@@ -115,3 +115,9 @@ class NoAdbError(base_error.BaseError):
   def __init__(self, msg=None):
     super(NoAdbError, self).__init__(
         msg or 'Unable to find adb.', is_infra_error=True)
+

[jbudorick, 2016/02/05 01:40:43]

nit: +1 blank line

[rnephew (Reviews Here), 2016/02/05 01:52:00]

Done.

+class DeviceChargingError(CommandFailedError):
+  """Exception for device charging errors."""
+
+  def __init__(self, message, device_serial=None):
+    super(DeviceChargingError, self).__init__(message, device_serial)