This reverts commit 68409634.

Reason for revert:
Breaks git-cl split.
https://bugs.chromium.org/p/chromium/issues/detail?id=1054888

Original change's description:
> Improve git cl split
>
> This CL changes the behavior of `git cl split` to split the change
> by the size of the resulting CLs. For now, this is based on the number
> of bytes changed, and not by the number of changed lines. Depending
> on the shape of change, this may still produce more CLs than expected
> (and possibly more than before).
>
> A future change will switch the split to be based on the number
> of affected lines, and also introduce a mode to base the split
> on the number of affected files.
>
> Bug: 998922
> Change-Id: I49f868972a61b89b426ef9e2ceedc733eacb4350
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1778744
> Commit-Queue: Yannic Bonenberger <yannic.bonenberger@gmail.com>
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>

TBR=fdoray@chromium.org,dpranke@chromium.org,yannic.bonenberger@gmail.com,infra-scoped@luci-project-accounts.iam.gserviceaccount.com

Bug: 998922
Change-Id: I466e1245d5f1c934443d850c48c42d3e694e71c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2080205Reviewed-by: Anthony Polito <apolito@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>