Support formatting python3 scripts (reland)
Support formatting python3 scripts (reland)

Original CL: https://crrev.com/c/2241792

Fix Windows use case by calling yapf directly without going through
yapf.bat.

Bug: 1062053,1095581
Change-Id: I31a9f09cba655d6ac1b4da9874a24a41aa007b17
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2249606
Commit-Queue: Edward Lesmes <d05609f027dc667cc37492b1dc1bdea5d60fa82a@chromium.org>
Reviewed-by: Edward Lesmes <d05609f027dc667cc37492b1dc1bdea5d60fa82a@chromium.org>
Auto-Submit: Peter Wen <53d52474b70a71c67f70feffe31c51d063609fa8@chromium.org>

CoherentLabs/depot_tools,CoherentLabs/depot_tools