Share more code between updateWidget implementations in HTMLEmbedElement and HTMLObje...

Share more code between updateWidget implementations in HTMLEmbedElement and HTMLObjectElement
https://bugs.webkit.org/show_bug.cgi?id=74340

Reviewed by Adam Barth.

I'm preparing to unify these two methods, and starting by sharing more code between them.

* html/HTMLEmbedElement.cpp:
(WebCore::HTMLEmbedElement::updateWidget):
* html/HTMLObjectElement.cpp:
(WebCore::HTMLObjectElement::updateWidget):
* html/HTMLPlugInElement.cpp:
(WebCore::HTMLPlugInElement::guardedDispatchBeforeLoadEvent):
* html/HTMLPlugInElement.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105932 268f45cc-cd09-0410-ab3c-d52691b4dbfc