Allow custom typeface deserializing of picture typefaces.

Serialization of typefaces for SK_PICT_TYPEFACE_TAG already have support
for custom serialization via SkSerialProcs.fTypefaceProc.  This adds the
mirror side of that, to make use of SkDeserialProcs.fTypefaceProc when
it is provided.

Bug: chromium:1044996
Change-Id: I58f7f43e2668d0ca1d0821551f9ca034975ed199
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/297617
Reviewed-by: Alan Screen <awscreen@chromium.org>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
2 files changed