Remove old functions in the process of renaming WebFontFamily to WebFallbackFont

Second blink side change, part 3 of the series in total.

BUG=382411
R=eae,behdad,tkent

Review URL: https://codereview.chromium.org/323963002

git-svn-id: svn://svn.chromium.org/blink/trunk@176207 bbb929c8-8fbe-4397-9dbb-9b2b20218538