[fontations] Use SkMatrix::mapRect for bounds mapping

The main motivation is to elimitate mutating path calls (transform), but
the new approach should also be cheaper/cleaner.

Change-Id: If9a0ecfe82546ad4a4783a5266b5a56ec6e6d2c0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1068096
Reviewed-by: Dominik Röttsches <drott@google.com>
Commit-Queue: Florin Malita <fmalita@google.com>
1 file changed