While we're at it, ensure that the working directory is reverted even if
exceptions are raised by moving that part into a finally block.
Bug: 1404222
Change-Id: I8606bc5810202ff1ecdc7f202e3f574bf643f91d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4129515
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Commit-Queue: Pavol Marko <pmarko@chromium.org>