Following the removal of the "Font Boosting" TEXT_AUTOSIZING implementation in <https://trac.webkit.org/changeset/206119> (bug #162167) repurpose the feature name TEXT_AUTOSIZING for the code guarded by IOS_TEXT_AUTOSIZING. At the time of writing, IOS_TEXT_AUTOSIZING is enabled on both macOS and iOS.
Created attachment 289491 [details] Patch
Created attachment 289600 [details] Patch
Created attachment 289603 [details] Patch
Committed r206395: <http://trac.webkit.org/changeset/206395>