Simplify blob's appendGlyph interface

Change-Id: I62fcaef94570982d46e678b8e128b02e2514a96a
Reviewed-on: https://skia-review.googlesource.com/145528
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed