Update copyright headers in testing/, tools/

The methodology used to generate this CL is documented in
https://crbug.com/1098010#c95.

No-Try: true
No-Presubmit: true
Bug: 1098010
Change-Id: I3a8a7b150e7bd64690534727150646081df50439
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3900697
Reviewed-by: Mark Mentovai <[email protected]>
Auto-Submit: Avi Drissman <[email protected]>
Owners-Override: Avi Drissman <[email protected]>
Commit-Queue: Avi Drissman <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1047644}
diff --git a/testing/test_env_user_script.py b/testing/test_env_user_script.py
index 1d943876..dc8d82a 100755
--- a/testing/test_env_user_script.py
+++ b/testing/test_env_user_script.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# Copyright (c) 2019 The Chromium Authors. All rights reserved.
+# Copyright 2019 The Chromium Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.