Make fetch compatible with Python 3

The scripts still work with Python 2.
There are no intended behaviour changes.

Bug: 939847
Change-Id: Icada60c5b2cf351d62aead26b7364fcef2c2a3e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1524486
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Raul Tambre <raul@tambre.ee>
diff --git a/gclient_utils.py b/gclient_utils.py
index 91692f8..48c023f 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -225,7 +225,7 @@
   if sys.platform == 'win32':
     # Give up and use cmd.exe's rd command.
     path = os.path.normcase(path)
-    for _ in xrange(3):
+    for _ in range(3):
       exitcode = subprocess.call(['cmd.exe', '/c', 'rd', '/q', '/s', path])
       if exitcode == 0:
         return