Revert "Drop py2 support in gerrit and git related files"

This reverts commit b5c7f4b46c.

Reason for revert: missing a replace for urlparse.urlparse

Original change's description:
> Drop py2 support in gerrit and git related files
>
> python3 is the only supported version of python in depot_tools.
>
> Bug: 1475402
> Change-Id: Ie4ee18d297081b3aa0206b8d7ce6461819bff0ca
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4809560
> Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
> Commit-Queue: Gavin Mak <gavinmak@google.com>

Bug: 1475402
Change-Id: Idd00fdfe0b3d62785da2789a7dfcc9fbc79b6385
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4811623
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>

git_cache.py

@@ -5,7 +5,10 @@
 
 """A git command for managing a local cache of git repositories."""
 
+from __future__ import print_function
+
 import contextlib
+import errno
 import logging
 import optparse
 import os
@@ -15,7 +18,11 @@ import sys
 import tempfile
 import threading
 import time
-import urllib.parse
+
+try:
+  import urlparse
+except ImportError:  # For Py3 compatibility
+  import urllib.parse as urlparse
 
 from download_from_google_storage import Gsutil
 import gclient_utils
@@ -135,7 +142,7 @@ class Mirror(object):
     b = os.getenv('OVERRIDE_BOOTSTRAP_BUCKET')
     if b:
       return b
-    u = urllib.parse.urlparse(self.url)
+    u = urlparse.urlparse(self.url)
     if u.netloc == 'chromium.googlesource.com':
       return 'chromium-git-cache'
     # Not recognized.
@@ -157,7 +164,7 @@ class Mirror(object):
       url = os.path.splitdrive(url)[1]
       return url.replace('-', '--').replace(os.sep, '-')
 
-    parsed = urllib.parse.urlparse(url)
+    parsed = urlparse.urlparse(url)
     norm_url = parsed.netloc + parsed.path
     if norm_url.endswith('.git'):
       norm_url = norm_url[:-len('.git')]
@@ -352,7 +359,7 @@ class Mirror(object):
 
   def supported_project(self):
     """Returns true if this repo is known to have a bootstrap zip file."""
-    u = urllib.parse.urlparse(self.url)
+    u = urlparse.urlparse(self.url)
     return u.netloc in [
         'chromium.googlesource.com',
         'chrome-internal.googlesource.com']