Convert GrGlyph::PackedID to SkPackedGlyphID

This changes ripples through many areas of the code like the
hash map.

This will simplify making SkGlyphCache and GrTextStrike work
together in future CLs.

* Convert ctor to take an SkGlyph
* Remove many unused functions

Change-Id: I43ea414f03dfbb683ba7b46bf48a93c7a78895c6
Reviewed-on: https://skia-review.googlesource.com/c/179641
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
4 files changed