Revert "rely on clients to opt in to legacy enums"

This reverts commit 98f4e81d49dc18b0f174fa85ee697c9c364d1ab6.

Reason for revert: prolly broke google3

Original change's description:
> rely on clients to opt in to legacy enums
> 
> Bug: skia:8937
> Change-Id: I4cd9d44e87ce3309884d563c8e11336f0c39faf0
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/205934
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Reed <reed@google.com>
> Auto-Submit: Mike Reed <reed@google.com>

TBR=reed@google.com

Change-Id: I1a14e531b3718e27e161544dbc44d55582e1f83a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:8937
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206064
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed