Distinguish between glyphs with empty path and no path.

BUG=skia:4904

Change-Id: I065e3b4d8596b415ddaf094d7f9a4b65da64d4d4
Reviewed-on: https://skia-review.googlesource.com/117280
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Herb Derby <herb@google.com>
20 files changed