Remove Element::getAttributeItem() overload that returned a mutable Attribute*.
<http://webkit.org/b/109756>

Reviewed by Antti Koivisto.

Remove this to prevent callers from accidentally causing elements to convert to UniqueElementData.
There are two call sites (Attr and HTMLSelectElement) that legitimately need to mutate Attribute
objects in-place, they now use Element::ensureUniqueElementData()->getAttributeItem() directly instead.

Small progression on Membuster3, mostly for peace of mind.

* dom/Attr.cpp:
(WebCore::Attr::elementAttribute):
* dom/Element.h:
(Element):
* html/HTMLInputElement.cpp:
(WebCore::HTMLInputElement::updateType):
* html/HTMLSelectElement.cpp:
(WebCore::HTMLSelectElement::parseAttribute):
* svg/SVGStyledElement.cpp:
(WebCore::SVGStyledElement::getPresentationAttribute):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@142827 268f45cc-cd09-0410-ab3c-d52691b4dbfc
6 files changed