Remove implicit/global assumptions which could affect tests. Bug: b/351071334 Change-Id: Ie266228f404b768cb539fdc17dddbbb13693e939 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5723208 Reviewed-by: Robbie Iannucci <iannucci@chromium.org> Commit-Queue: Allen Li <ayatane@chromium.org> Reviewed-by: Yiwei Zhang <yiwzhang@google.com>