Update from https://crrev.com/309415

build/android/pylib/remote/device/remote_device_environment.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.
 
 """Environment setup and teardown for remote devices."""
 
 import logging
 import os
 import sys
 
@@ skipping 64 matching lines @@
     self._GetAccessToken()
     if self._trigger:
       self._device = self._SelectDevice()
 
   def TearDown(self):
     """Teardown the test environment."""
     self._RevokeAccessToken()
 
   def __enter__(self):
     """Set up the test run when used as a context manager."""
-    self.SetUp()
-    return self
+    try:
+      self.SetUp()
+      return self
+    except:
+      self.__exit__(*sys.exc_info())
+      raise
 
   def __exit__(self, exc_type, exc_val, exc_tb):
     """Tears down the test run when used as a context manager."""
     self.TearDown()
 
   def _GetAccessToken(self):
     """Generates access token for remote device service."""
     logging.info('Generating remote service access token')
     access_token_results = appurify_sanitized.api.access_token_generate(
         self._api_key, self._api_secret)
@@ skipping 14 matching lines @@
     logging.info('Finding %s with %s to run tests on.' %
         (self._remote_device, self._remote_device_os))
     dev_list_res = appurify_sanitized.api.devices_list(self._access_token)
     remote_device_helper.TestHttpResponse(dev_list_res,
                                           'Unable to generate access token.')
     device_list = dev_list_res.json()['response']
     for device in device_list:
       if (device['name'] == self._remote_device
           and device['os_version'] == self._remote_device_os):
         return device['device_type_id']
-    raise remote_device_helper.RemoteDeviceError(
-        'No device found: %s %s' % (self._remote_device,
-        self._remote_device_os))
+    self._NoDeviceFound(device_list)
+
+  def _PrintAvailableDevices(self, device_list):
+    def compare_devices(a,b):
+      for key in ('os_version', 'name'):
+        c = cmp(a[key], b[key])
+        if c:
+          return c
+      return 0
+
+    logging.critical('Available Android Devices:')
+    android_devices = (d for d in device_list if d['os_name'] == 'Android')
+    for d in sorted(android_devices, compare_devices):
+      logging.critical('  %s %s', d['os_version'].ljust(7), d['name'])
+
+  def _NoDeviceFound(self, device_list):
+    self._PrintAvailableDevices(device_list)
+    raise remote_device_helper.RemoteDeviceError('No device found: %s %s' %
+        (self._remote_device, self._remote_device_os))
 
   @property
   def device(self):
     return self._device
 
   @property
   def token(self):
     return self._access_token
 
   @property
   def results_path(self):
     return self._results_path
 
   @property
   def runner_type(self):
     return self._runner_type
 
   @property
   def runner_package(self):
     return self._runner_package
 
   @property
   def trigger(self):
     return self._trigger
 
   @property
   def collect(self):
     return self._collect