[Android] Unit tests for DeviceUtils.

build/android/pylib/device/decorators.py

 # Copyright 2014 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.
 
 """
 Function/method decorators that provide timeout and retry logic.
 """
 
 import functools
 import os
@@ skipping 32 matching lines @@
     timeout = timeout_func(*args, **kwargs)
     retries = retries_func(*args, **kwargs)
     if pass_values:
       kwargs['timeout'] = timeout
       kwargs['retries'] = retries
     def impl():
       return f(*args, **kwargs)
     try:
       return timeout_retry.Run(impl, timeout, retries)
     except old_errors.WaitForResponseTimedOutError as e:
-      raise device_errors.CommandTimeoutError(str(e))
+      raise device_errors.CommandTimeoutError(str(e)), None, (
+             sys.exc_info()[2])
     except old_errors.DeviceUnresponsiveError as e:
-      raise device_errors.DeviceUnreachableError(str(e))
+      raise device_errors.DeviceUnreachableError(str(e)), None, (
+             sys.exc_info()[2])
     except reraiser_thread.TimeoutError as e:
-      raise device_errors.CommandTimeoutError(str(e))
+      raise device_errors.CommandTimeoutError(str(e)), None, (
+             sys.exc_info()[2])
   return TimeoutRetryWrapper
 
 
 def WithTimeoutAndRetries(f):
   """A decorator that handles timeouts and retries.
 
   'timeout' and 'retries' kwargs must be passed to the function.
 
   Args:
     f: The function to decorate.
@@ skipping 68 matching lines @@
     The actual decorator.
   """
   def decorator(f):
     def get_timeout(inst, *_args, **kwargs):
       return kwargs.get('timeout', getattr(inst, default_timeout_name))
     def get_retries(inst, *_args, **kwargs):
       return kwargs.get('retries', getattr(inst, default_retries_name))
     return _TimeoutRetryWrapper(f, get_timeout, get_retries, pass_values=True)
   return decorator