Use CreateProcess instead of subprocess.Popen to launch Chrome in the mini_installer test framework.

chrome/test/mini_installer/launch_chrome.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.
 
 """Launches Chrome.
 
 This script launches Chrome and waits until its window shows up.
 """
 
 import optparse
-import subprocess
 import sys
 import time
+import win32process
 
 import chrome_helper
 
 
 def WaitForWindow(process_id, class_pattern):
   """Waits until a window specified by |process_id| and class name shows up.
 
   Args:
     process_id: The ID of the process that owns the window.
     class_pattern: The regular expression pattern of the window class name.
@@ skipping 11 matching lines @@
 
 
 def main():
   usage = 'usage: %prog chrome_path'
   parser = optparse.OptionParser(usage, description='Launch Chrome.')
   _, args = parser.parse_args()
   if len(args) != 1:
     parser.error('Incorrect number of arguments.')
   chrome_path = args[0]
 
-  process = subprocess.Popen(chrome_path)
-  if not WaitForWindow(process.pid, 'Chrome_WidgetWin_'):
+  # Use CreateProcess rather than subprocess.Popen to avoid side effects such as
+  # handle interitance.
+  _, _, process_id, _ = win32process.CreateProcess(None, chrome_path, None,
+                                                   None, 0, 0, None, None,
+                                                   win32process.STARTUPINFO())
+  if not WaitForWindow(process_id, 'Chrome_WidgetWin_'):
     raise Exception('Could not launch Chrome.')
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())