Fix invalid Python file encoding "utf8"
Since Python 3 it must be "utf-8", which is the official name.
This is backwards compatible with Python 2.
Bug: 962277
Change-Id: I21115a322944532f1870862c8c048f8455c1109f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1608562
Auto-Submit: Raul Tambre <raul@tambre.ee>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
diff --git a/checkout.py b/checkout.py
index 2bcf984..7e91afc 100644
--- a/checkout.py
+++ b/checkout.py
@@ -1,4 +1,4 @@
-# coding=utf8
+# coding=utf-8
# Copyright (c) 2012 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.