ImageBufferBackend::clearContents() is redundant function. It is almost not used at all and it is overloading functionality that already exist.
<rdar://problem/106020763>
Pull request: https://github.com/WebKit/WebKit/pull/10787
Committed 261057@main (433f17507ed5): <https://commits.webkit.org/261057@main> Reviewed commits have been landed. Closing PR #10787 and removing active labels.