Revert "Simplify SkTypeface::charsToGlyphs API to require UTF32 input"

This reverts commit fde841de44a63701b0a4396da35893f348559ce9.

Reason for revert: used in headless on google3, need to add a guard

Original change's description:
> Simplify SkTypeface::charsToGlyphs API to require UTF32 input
> 
> Change-Id: I486713c496c40103eef13fa6068ac4d69e32f606
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/207865
> Commit-Queue: Ben Wagner <bungeman@google.com>
> Reviewed-by: Ben Wagner <bungeman@google.com>

TBR=bungeman@google.com,herb@google.com,reed@google.com

Change-Id: I1d28ed5c31deaa76aa3c4b627454b0ad3356a6fc
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/208800
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Reed <reed@google.com>
27 files changed