Use cleanup with retry on Windows for all scripts.

utils.py

 #!/usr/bin/python
 # 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.
 
 """Utilities for all our deps-management stuff."""
 
 import hashlib
 import os
 import shutil
 import sys
 import subprocess
 import tarfile
 import time
 import zipfile
 
 
 def RunSubprocessWithRetry(cmd):
   """Invokes the subprocess and backs off exponentially on fail."""
   for i in range(5):
     try:
       subprocess.check_call(cmd)
       return
     except subprocess.CalledProcessError as exception:
       backoff = pow(2, i)
       print 'Got %s, retrying in %d seconds...' % (exception, backoff)
       time.sleep(backoff)
-  
+
   print 'Giving up.'
   raise exception
 
 
 def DownloadFilesFromGoogleStorage(path):
   print 'Downloading files in %s...' % path
 
   extension = 'bat' if 'win32' in sys.platform else 'py'
   cmd = ['download_from_google_storage.%s' % extension,
          '--bucket=chromium-webrtc-resources',
@@ skipping 10 matching lines @@
   sha1 = hashlib.sha1()
   file_to_hash = open(path, 'rb')
   try:
     sha1.update(file_to_hash.read())
   finally:
     file_to_hash.close()
 
   return sha1.hexdigest()
 
 
+# Code partially copied from
+# https://cs.chromium.org#chromium/build/scripts/common/chromium_utils.py
+def RemoveDirectory(*path):
+  """Recursively removes a directory, even if it's marked read-only.
+
+  Remove the directory located at *path, if it exists.
+
+  shutil.rmtree() doesn't work on Windows if any of the files or directories
+  are read-only, which svn repositories and some .svn files are.  We need to
+  be able to force the files to be writable (i.e., deletable) as we traverse
+  the tree.
+
+  Even with all this, Windows still sometimes fails to delete a file, citing
+  a permission error (maybe something to do with antivirus scans or disk
+  indexing).  The best suggestion any of the user forums had was to wait a
+  bit and try again, so we do that too.  It's hand-waving, but sometimes it
+  works. :/
+  """
+  file_path = os.path.join(*path)
+  if not os.path.exists(file_path):
+    return
+
+  if sys.platform == 'win32':
+    # Give up and use cmd.exe's rd command.
+    file_path = os.path.normcase(file_path)
+    for _ in xrange(3):
+      print 'RemoveDirectory running %s' % (' '.join(
+          ['cmd.exe', '/c', 'rd', '/q', '/s', file_path]))
+      if not subprocess.call(['cmd.exe', '/c', 'rd', '/q', '/s', file_path]):
+        break
+      print '  Failed'
+      time.sleep(3)
+    return
+  else:
+    shutil.rmtree(file_path, ignore_errors=True)
+
+
 def DeleteDirNextToGclient(directory):
   # Sanity check to avoid nuking the wrong dirs.
   if not os.path.exists('.gclient'):
     raise Exception('Invoked from wrong dir; invoke from dir with .gclient')
   print 'Deleting %s in %s...' % (directory, os.getcwd())
-  shutil.rmtree(directory, ignore_errors=True)
+  RemoveDirectory(directory)
 
 
 def UnpackToWorkingDir(archive_path):
   extension = os.path.splitext(archive_path)[1]
   if extension == '.zip':
     _Unzip(archive_path)
   else:
     _Untar(archive_path)
 
 
@@ skipping 17 matching lines @@
 
 def GetPlatform():
   if sys.platform.startswith('win'):
     return 'win'
   if sys.platform.startswith('linux'):
     return 'linux'
   if sys.platform.startswith('darwin'):
     return 'mac'
   raise Exception("Can't run on platform %s." % sys.platform)