Make CSSMappedAttributeDeclaration have CSSMutableStyleDeclaration instead of being one

Make CSSMappedAttributeDeclaration have CSSMutableStyleDeclaration instead of being one
https://bugs.webkit.org/show_bug.cgi?id=77545

Reviewed by Andreas Kling.

This is the easiest path for eliminating the last remaining subclass of CSSMutableStyleDeclaration.

On negative side this increases memory use of CSSMappedAttributeDeclaration by one ptr and refcount
(it loses the vptr) in total.

This is not meant to be the end state, just an intermediate refactoring step. CSSMappedAttributeDeclaration
should clearly be renamed too but this patch doesn't do that. It might not exist in its current form
much longer.

* css/CSSMutableStyleDeclaration.cpp:
(WebCore::CSSMutableStyleDeclaration::setProperty):
(WebCore::CSSMutableStyleDeclaration::merge):
* css/CSSMutableStyleDeclaration.h:

    Remove protected section. No subclasses remain.
    Rename setPropertyInternal() to setProperty(). All public methods here are internal.

(CSSMutableStyleDeclaration):
* css/CSSParser.cpp:
(WebCore::CSSParser::parseMappedAttributeValue):
* dom/Attribute.cpp:
(WebCore::Attribute::clone):
* dom/Attribute.h:
(Attribute):
(WebCore::Attribute::decl):
(WebCore::Attribute::mappedAttributeDeclaration):
(WebCore::Attribute::setMappedAttributeDeclaration):
(WebCore::Attribute::Attribute):
* dom/CSSMappedAttributeDeclaration.cpp:
(WebCore::CSSMappedAttributeDeclaration::setMappedImageProperty):
(WebCore::CSSMappedAttributeDeclaration::setMappedProperty):
(WebCore::CSSMappedAttributeDeclaration::removeMappedProperty):
* dom/CSSMappedAttributeDeclaration.h:
(CSSMappedAttributeDeclaration):
(WebCore::CSSMappedAttributeDeclaration::declaration):
(WebCore::CSSMappedAttributeDeclaration::CSSMappedAttributeDeclaration):

    Make CSSMutableStyleDeclaration a member instead of the base class.

* dom/StyledElement.cpp:
(WebCore::StyledElement::attributeChanged):
(WebCore::StyledElement::removeCSSProperty):
(WebCore::StyledElement::addCSSProperty):
(WebCore::StyledElement::addCSSImageProperty):
(WebCore::StyledElement::addCSSLength):
(WebCore::StyledElement::addCSSColor):
(WebCore::StyledElement::createMappedDecl):
* svg/SVGStyledElement.cpp:
(WebCore::SVGStyledElement::getPresentationAttribute):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106471 268f45cc-cd09-0410-ab3c-d52691b4dbfc