This is a followup of Bug 153903 to cleanup Cleanup KeyboardEvent::createForDummy(), which is created temporarily to work around the DOM.mm::(DOMNode *)nextFocusNode and DOM.mm::(DOMNode *)previousFocusNode.
<rdar://problem/24598613>
This commit removed this function: https://github.com/WebKit/WebKit/commit/1c2c87fa05a9a6b4a9e4d5f114dbf6b54153d88a Do we need to do anything else?
Seems safe to assume that was the cleanup.