depot_tools: Include httplib2 using vpython.

Bug: 1002153
Change-Id: I940b9d834c2f76caab2bd86fc5d5d5c3b03b4b46
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1871763
Reviewed-by: Anthony Polito <apolito@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
diff --git a/git_cl.py b/git_cl.py
index ab05f3e..0415fd4 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -16,6 +16,7 @@
 import datetime
 import glob
 import httplib
+import httplib2
 import itertools
 import json
 import logging
@@ -37,7 +38,6 @@
 import zlib
 
 from third_party import colorama
-from third_party import httplib2
 import auth
 import clang_format
 import dart_format