Update from https://crrev.com/314320

testing/chromoting/browser_tests_launcher.py

 # Copyright (c) 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.
 
 
 """Utility script to launch browser-tests on the Chromoting bot."""
 import argparse
 import glob
 import hashlib
 import os
 from os.path import expanduser
 import shutil
 import socket
 import subprocess
 
 BROWSER_TEST_ID = 'browser_tests'
 PROD_DIR_ID = '#PROD_DIR#'
 HOST_HASH_VALUE = hashlib.md5(socket.gethostname()).hexdigest()
 SUCCESS_INDICATOR = 'SUCCESS: all tests passed.'
 NATIVE_MESSAGING_DIR = 'NativeMessagingHosts'
 CRD_ID = 'chrome-remote-desktop'  # Used in a few file/folder names
 CHROMOTING_HOST_PATH = '/opt/google/chrome-remote-desktop/chrome-remote-desktop'
+TEST_FAILURE = False
 
 
 def LaunchBTCommand(command):
-  results, error = RunCommandInSubProcess(command)
+  global TEST_FAILURE
+  results = RunCommandInSubProcess(command)
 
   # Check that the test passed.
   if SUCCESS_INDICATOR not in results:
-    # Obtain contents of Chromoting host logs.
-    log_contents = ''
-    # There should be only 1 log file, as we delete logs on test completion.
-    # Loop through matching files, just in case there are more.
-    for log_file in glob.glob('/tmp/chrome_remote_desktop_*'):
-      with open(log_file, 'r') as log:
-        log_contents += '\nHOST LOG %s CONTENTS:\n%s' % (log_file, log.read())
-    print log_contents
-    raise Exception(
-        'Test failed. Command:%s\nResults:%s\nError:%s\n' %
-        (command, results, error))
+    TEST_FAILURE = True
 
 
 def RunCommandInSubProcess(command):
   """Creates a subprocess with command-line that is passed in.
 
   Args:
     command: The text of command to be executed.
   Returns:
     results: stdout contents of executing the command.
-    error: stderr contents.
   """
 
   cmd_line = [command]
   try:
     p = subprocess.Popen(cmd_line, stdout=subprocess.PIPE, shell=True)
     results, error = p.communicate()
   except subprocess.CalledProcessError, e:
     raise Exception('Exception %s running command %s\nError: %s' %
                     (e, command, error))
   else:
     print results
-  return results, error
+  return results
 
 
 def TestCleanUp(user_profile_dir):
   """Cleans up test machine so as not to impact other tests.
 
   Args:
     user_profile_dir: the user-profile folder used by Chromoting tests.
 
   """
   # Stop the host service.
   RunCommandInSubProcess(CHROMOTING_HOST_PATH + ' --stop')
 
   # Cleanup any host logs.
   RunCommandInSubProcess('rm /tmp/chrome_remote_desktop_*')
 
   # Remove the user-profile dir
   if os.path.exists(user_profile_dir):
     shutil.rmtree(user_profile_dir)
 
 
 def InitialiseTestMachineForLinux(cfg_file):
   """Sets up a Linux machine for connect-to-host browser-tests.
 
   Copy over me2me host-config to expected locations.
   By default, the Linux me2me host expects the host-config file to be under
   $HOME/.config/chrome-remote-desktop
   Its name is expected to have a hash that is specific to a machine.
 
-  TODO(anandc):
-  Once we have Linux machines in the swarming lab already installed with the
-  me2me host, this function should also perform the step of starting the host.
-  That is gated on this CL: https://chromereviews.googleplex.com/123957013/, and
-  then having base images in the chrome-labs be updated with it.
-
   Args:
     cfg_file: location of test account's host-config file.
   """
 
   # First get home directory on current machine.
   home_dir = expanduser('~')
   default_config_file_location = os.path.join(home_dir, '.config', CRD_ID)
   if os.path.exists(default_config_file_location):
     shutil.rmtree(default_config_file_location)
   os.makedirs(default_config_file_location)
 
   # Copy over test host-config to expected location, with expected file-name.
   # The file-name should contain a hash-value that is machine-specific.
   default_config_file_name = 'host#%s.json' % HOST_HASH_VALUE
   config_file_src = os.path.join(os.getcwd(), cfg_file)
   shutil.copyfile(
       config_file_src,
       os.path.join(default_config_file_location, default_config_file_name))
 
   # Finally, start chromoting host.
   RunCommandInSubProcess(CHROMOTING_HOST_PATH + ' --start')
 
 
 def SetupUserProfileDir(me2me_manifest_file, it2me_manifest_file,
                         user_profile_dir):
-  """Sets up the Google Chrome user profile directory
+  """Sets up the Google Chrome user profile directory.
 
   Delete the previous user profile directory if exists and create a new one.
   This invalidates any state changes by the previous test so each test can start
   with the same environment.
 
   When a user launches the remoting web-app, the native messaging host process
   is started. For this to work, this function places the me2me and it2me native
   messaging host manifest files in a specific folder under the user-profile dir.
 
   Args:
@@ skipping 39 matching lines @@
     for line in f:
       # Reset the user profile directory to start each test with a clean slate.
       SetupUserProfileDir(args.me2me_manifest_file, args.it2me_manifest_file,
                           args.user_profile_dir)
 
       # Replace the PROD_DIR value in the command-line with
       # the passed in value.
       line = line.replace(PROD_DIR_ID, args.prod_dir)
       LaunchBTCommand(line)
 
+  # Was there any test failure?
+  if TEST_FAILURE:
+    # Obtain contents of Chromoting host logs.
+    log_contents = ''
+    # There should be only 1 log file, as we delete logs on test completion.
+    # Loop through matching files, just in case there are more.
+    for log_file in glob.glob('/tmp/chrome_remote_desktop_*'):
+      with open(log_file, 'r') as log:
+        log_contents += '\nHOST LOG %s\n CONTENTS:\n%s' % (log_file, log.read())
+    print log_contents
+    raise Exception('At least one test failed.')
+
   # Now, stop host, and cleanup user-profile-dir
   TestCleanUp(args.user_profile_dir)
 
 if __name__ == '__main__':
   main()