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/auth.py b/auth.py
index 494e618..1123cf7 100644
--- a/auth.py
+++ b/auth.py
@@ -9,14 +9,13 @@
 import collections
 import datetime
 import functools
+import httplib2
 import json
 import logging
 import os
 
 import subprocess2
 
-from third_party import httplib2
-
 
 # This is what most GAE apps require for authentication.
 OAUTH_SCOPE_EMAIL = 'https://www.googleapis.com/auth/userinfo.email'