Remove SK_LEGACY_FONTMGR_FACTORY.

SkFontMgr factories now return sk_sp and the legacy factories are no
longer used and can be removed.

BUG=skia:5077

Change-Id: Ieaff8555b297d1db157f8b78cdd6e7d07a3b5490
Reviewed-on: https://skia-review.googlesource.com/6894
Commit-Queue: Ben Wagner <bungeman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
24 files changed