This reverts commit 3b4f862d05.
Reason for revert: might have caused chromium:1326848
Original change's description:
> Remove DSLWrapper helper class.
>
> Without an `operator=` on our expressions and variables, we no longer
> need to wrap all our expressions with a helper.
>
> Change-Id: I8110079f61c9ad01997f7c4b376db223dc4b6e17
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/541063
> Commit-Queue: John Stiles <johnstiles@google.com>
> Auto-Submit: John Stiles <johnstiles@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>
Change-Id: I7efb3004913f7c85dc551d9740a6b31971de52d2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/541736
Auto-Submit: John Stiles <johnstiles@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
37c03c8d73