[Android] Improve exception message when failed to get test list.

build/android/pylib/gtest/setup.py

 # Copyright 2013 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.
 
 """Generates test runner factory and tests for GTests."""
 
 import fnmatch
 import glob
 import logging
 import os
@@ skipping 43 matching lines @@
     'system_wrappers_unittests':
       'system_wrappers/source/system_wrappers_unittests.isolate',
     'test_support_unittests': 'test/test_support_unittests.isolate',
     'tools_unittests': 'tools/tools_unittests.isolate',
     'video_engine_core_unittests':
       'video_engine/video_engine_core_unittests.isolate',
     'voice_engine_unittests': 'voice_engine/voice_engine_unittests.isolate',
 }
 
 # Append the WebRTC tests with the full path from Chromium's src/ root.
-for test,isolate_path in _WEBRTC_ISOLATE_FILE_PATHS.items():
+for test, isolate_path in _WEBRTC_ISOLATE_FILE_PATHS.items():
   _ISOLATE_FILE_PATHS[test] = 'third_party/webrtc/%s' % isolate_path
 
 # Used for filtering large data deps at a finer grain than what's allowed in
 # isolate files since pushing deps to devices is expensive.
 # Wildcards are allowed.
 _DEPS_EXCLUSION_LIST = [
     'chrome/test/data/extensions/api_test',
     'chrome/test/data/extensions/secure_shell',
     'chrome/test/data/firefox*',
     'chrome/test/data/gpu',
@@ skipping 129 matching lines @@
 
   Returns:
     All the tests in the test suite.
   """
   for device in devices:
     try:
       logging.info('Obtaining tests from %s', device)
       return runner_factory(device, 0).GetAllTests()
     except (android_commands.errors.WaitForResponseTimedOutError,
             android_commands.errors.DeviceUnresponsiveError), e:
-      logging.warning('Failed obtaining tests from %s with exception: %s',
+      logging.warning('Failed obtaining test list from %s with exception: %s',
                       device, e)
-  raise Exception('No device available to get the list of tests.')
+  raise Exception('Failed to obtain test list from devices.')
 
 
 def _FilterTestsUsingPrefixes(all_tests, pre=False, manual=False):
   """Removes tests with disabled prefixes.
 
   Args:
     all_tests: List of tests to filter.
     pre: If True, include tests with PRE_ prefix.
     manual: If True, include tests with MANUAL_ prefix.
 
@@ skipping 84 matching lines @@
   if test_options.gtest_filter:
     tests = unittest_util.FilterTestNames(tests, test_options.gtest_filter)
 
   # Coalesce unit tests into a single test per device
   if test_options.suite_name != 'content_browsertests':
     num_devices = len(devices)
     tests = [':'.join(tests[i::num_devices]) for i in xrange(num_devices)]
     tests = [t for t in tests if t]
 
   return (TestRunnerFactory, tests)