Refix perspective for glyph drawing of last resort

This is a redo of:
https://skia-review.googlesource.com/c/skia/+/553593

Turns out the getMaxScale returns -1 when given a perspective matrix.
Seems like the best guess for a perspective situation is I.

Change-Id: I79ddd5d6b07c39ffd6f50a5e636cea30d7f399ae
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/554076
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
1 file changed