tool tip/alt. text appears when mouse is no longer hovering over link

tool tip/alt. text appears when mouse is no longer hovering over link
https://bugs.webkit.org/show_bug.cgi?id=24427
<rdar://problem/8045235>

Reviewed by Antonio Gomes.

Although the bug no longer reproduces, add a manual test that can be used to determine if a
tooltip for a hyperlink is shown when the cursor no longer hovers over it.

* ManualTests/tooltip-when-mouse-not-directly-over-hyperlink.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@198922 268f45cc-cd09-0410-ab3c-d52691b4dbfc