Remove SkMulDiv.

This removes the last use of SkMulDiv. This last use was in the
conversion code for FontConfig widths and weights which is modified to
use SkScaler instead of SkFixed.

Change-Id: Ia20a2066cbc42e986c44fc573829edf86973846e
Reviewed-on: https://skia-review.googlesource.com/134426
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
3 files changed