Introduced in https://bugs.webkit.org/show_bug.cgi?id=43507, ImageBuffer::drawsUsingCopy was used to know whether or not an ImageBuffer should be explicitly copied before being painted into a context (as was used in HTMLCanvasElement::paint). All platforms now handle the logic of copying or not in their ImageBuffer::draw() implementations, so drawsUsingCopy() is no longer needed.
Created attachment 101239 [details] Patch
Committed r91228: <http://trac.webkit.org/changeset/91228>