Update from https://crrev.com/304715

build/android/pylib/android_commands.py

 # Copyright (c) 2012 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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 # pylint: disable-all
 
@@ skipping 1909 matching lines @@
   def DisableUsbCharging(self, timeout=10):
     command = self._GetControlUsbChargingCommand()
     if not command:
       raise Exception('Unable to act on usb charging.')
     disable_command = command['disable_command']
     t0 = time.time()
     # Do not loop directly on self.IsDeviceCharging to cut the number of calls
     # to the device.
     while True:
       if t0 + timeout - time.time() < 0:
-        raise pexpect.TIMEOUT('Unable to enable USB charging in time.')
+        raise pexpect.TIMEOUT('Unable to disable USB charging in time: %s' % (
+            self.GetBatteryInfo()))
       self.RunShellCommand(disable_command)
       if not self.IsDeviceCharging():
         break
 
   def EnableUsbCharging(self, timeout=10):
     command = self._GetControlUsbChargingCommand()
     if not command:
       raise Exception('Unable to act on usb charging.')
     disable_command = command['enable_command']
     t0 = time.time()
@@ skipping 24 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()