Revert "Remove ppapi/generators"

This reverts commit 58084f46f6fa40d3dd10b4abf638e1c9615392be.

Reason for revert: Causing build failure:
https://ci.chromium.org/ui/p/chromium/builders/ci/win-archive-rel/55034/overview

Bug: 40511454
Original change's description:
> Remove ppapi/generators
>
> Bug: 40511454
> Change-Id: I16664da6b70a4eda1a5eaf495cf8f5db896d72de
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6729535
> Auto-Submit: Nico Weber <thakis@chromium.org>
> Commit-Queue: Derek Schuff <dschuff@chromium.org>
> Reviewed-by: Derek Schuff <dschuff@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1485713}

Bug: 40511454
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I78a67805fcb17515e7e2e2a6322cc225c04343e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6729435
Owners-Override: Wenyu Fu <wenyufu@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Wenyu Fu <wenyufu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1485720}
NOKEYCHECK=True
GitOrigin-RevId: 0bc4bd4c472d56118db9bf89b4894a45de382c24