ort is faster and fixes bugs in recursive strategy.

Bug: 1260085
Change-Id: Ib8523d45da5cb0beea957b6ab706101d55bdc1f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3276506
Commit-Queue: Anthony Polito <apolito@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Anthony Polito <apolito@google.com>