This update is per http://crrev.com/1031130 where OSS licensing
requested removal of "All rights reserved" from new files.

Change-Id: I52a9deab99539ea90403798606c7bbeb261df994
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3811744
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
Auto-Submit: Robert Liao <robliao@chromium.org>
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>