Remove SkUseTestFontConfigFile.

This method and its associated globals are no longer used by any user
and can now be removed.

BUG=skia:2817

Change-Id: Ia627e2494f568a733999b980aec9284467d2640d
Reviewed-on: https://skia-review.googlesource.com/6821
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
2 files changed