Revert "Clean up unflattening paints"

This reverts commit 717ef9472b56777f3f357705425d91b5373c9ae3.

Reason for revert: Blocking the G3 roll

Original change's description:
> Clean up unflattening paints
>
> Just removing legacy cruft for fonts, and also change to return by
> value (cleaner).
>
> Change-Id: If120931119c32542e06801da2b6d60ba84ba2186
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437676
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=bungeman@google.com,fmalita@chromium.org,reed@google.com,skcq-be@skia-corp.google.com.iam.gserviceaccount.com

Change-Id: If735d0212412c0262a6ccb52e7dd224a255906cf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437678
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
8 files changed