SSIA It seems to be unused and using 'searchfox.org', I looked into, if it has any superclass but it does not. Plus after removing in local branch, it compiles and does not seems to reflect any error etc. Thanks!
PR Attempt: https://github.com/WebKit/WebKit/pull/21051 Chris suggested on Slack that it is utility function and can be leveraged in future, so it should not be deleted. Marking this as "RESOLVED WONTFIX".