This allows git-cl to run successfully when the depot tools are installed to a path with a space in it.

Change-Id: I79fa44d13f89fb0ee1baaa90961b4c4284913c40
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2125626
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>