This reverts commit b3778411.

Reason for revert: <INSERT REASONING HERE>
Skia still has problems

Original change's description:
> Reland "depot_tools: Use vpython to execute fetch."
> 
> This is a reland of 028367fe
> 
> Should work on Skia after https://skia-review.googlesource.com/c/skia/+/244116
> 
> Original change's description:
> > depot_tools: Use vpython to execute fetch.
> >
> > Bug: 1002153
> > Change-Id: I11286bebc23bedada239d6ddb8ebb86207a41485
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1815707
> > Reviewed-by: Anthony Polito <apolito@google.com>
> > Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
> > Auto-Submit: Edward Lesmes <ehmaldonado@chromium.org>
> 
> Bug: 1002153
> Change-Id: Ifdde3c4a817ab6ca222c82c5448d630e85bf2a4b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1827719
> Reviewed-by: Anthony Polito <apolito@google.com>
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

TBR=ehmaldonado@chromium.org,jcgregorio@chromium.org,apolito@google.com

Change-Id: I1963c5bccf36692209dfe10aa30d77650e40c6f1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1002153
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1829971Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>