QualifiedName should use RefPtr<QualifiedNameImpl> internally.
<https://webkit.org/b/132796>

We were not inlining ~QualifiedName() and it was showing up in some
profiles (over 1% on dom-attr.html.)

This patch modernizes QualifiedName a bit by using RefPtr to store
the QualifiedNameImpl instead of doing manual ref() and deref()
in out-of-line functions.

Reviewed by Darin Adler.

* WebCore.exp.in:
* dom/QualifiedName.cpp:
(WebCore::QNameComponentsTranslator::translate):
(WebCore::QualifiedName::QualifiedName):
(WebCore::QualifiedName::~QualifiedName): Deleted.
(WebCore::QualifiedName::deref): Deleted.
* dom/QualifiedName.h:
(WebCore::QualifiedName::QualifiedNameImpl::create):
(WebCore::QualifiedName::QualifiedName):
(WebCore::QualifiedName::isHashTableDeletedValue):
(WebCore::QualifiedName::~QualifiedName):
(WebCore::QualifiedName::operator=):
(WebCore::QualifiedName::impl):
(WebCore::QualifiedName::ref): Deleted.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@170816 268f45cc-cd09-0410-ab3c-d52691b4dbfc