Typing an automatic text replacement phrase after a br in contenteditable is not...

Typing an automatic text replacement phrase after a br in contenteditable is not rendered as expected
https://bugs.webkit.org/show_bug.cgi?id=133883

Reviewed by Enrica Casucci.

enclosingDeletableElement() makes sure that the element's container is editable, but not
that it is capable of having content inside it (like how a <br> can't).

No new tests. I don't think this is testable because it requires setting some state in System Preferences.

* editing/DeleteButtonController.cpp:
(WebCore::enclosingDeletableElement):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@170655 268f45cc-cd09-0410-ab3c-d52691b4dbfc