add parameter names

Functions in SkPaint and SkCanvas are easier to write
about when all of their parameters are named.

Also, move GlyphCacheProc to private since the only
interface that returns it is already in private.

R=reed@google.com

Change-Id: Iaea46213d5614d564c1c3de99e6f96c5efaec4b1
Reviewed-on: https://skia-review.googlesource.com/16175
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>
2 files changed