Remove all empty glyph processing

The empty glyph processing is no longer needed since moving
the SkRemoteGlyphsCache to using getGlyphMetrics for tracking
glyph cache changes.

Change-Id: Iacf218b7d6eccc924181ea086792c0e8d7922ba0
Reviewed-on: https://skia-review.googlesource.com/c/193033
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
2 files changed