This reverts commit 1c8026d2.

Reason for revert:
Description should be set from gerrit before parsing the changes.

Original change's description:
> presubmit_support: Add --all-files options.
> 
> Will be set when --all is passed to git-cl presubmit to execute
> presubmit checks over all files on a repo.
> 
> Bug: 1042324
> Change-Id: I2ebb7c3ec633f9d3a3774314799aa056bc2919c8
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2003071
> Reviewed-by: Anthony Polito <apolito@google.com>
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

TBR=ehmaldonado@chromium.org,apolito@google.com,infra-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I8c455a269cdd6eb3dea9379faf351a04644bd23f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1042324, 1048885
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2038052Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>