Rename/tweak some StylePropertySet/CSSStyleDeclaration copying functions.
<http://webkit.org/b/114569>

Reviewed by Anders Carlsson.

- StylePropertySet::copy() -> mutableCopy()

    This function now returns a MutableStylePropertySet, and this is also reflected in the name.

- CSSStyleDeclaration::copy() -> copyProperties()

    Renamed to reflect that it's the properties being copied, not the CSSStyleDeclaration.
    They also now return MutableStylePropertySets.

- StylePropertySet::copyPropertiesInSet()
- CSSStyleDeclaration::copyPropertiesInSet()

    These functions now return MutableStylePropertySets.

* css/CSSComputedStyleDeclaration.cpp:
(WebCore::CSSComputedStyleDeclaration::copyProperties):
(WebCore::CSSComputedStyleDeclaration::copyPropertiesInSet):
* css/CSSComputedStyleDeclaration.h:
(CSSComputedStyleDeclaration):
* css/CSSStyleDeclaration.h:
(CSSStyleDeclaration):
* css/PropertySetCSSStyleDeclaration.cpp:
(WebCore::PropertySetCSSStyleDeclaration::copyProperties):
* css/PropertySetCSSStyleDeclaration.h:
* css/StylePropertySet.cpp:
(WebCore::StylePropertySet::mutableCopy):
(WebCore::StylePropertySet::copyPropertiesInSet):
* css/StylePropertySet.h:
(StylePropertySet):
* css/StyleRule.cpp:
(WebCore::StyleRule::StyleRule):
(WebCore::StyleRule::mutableProperties):
(WebCore::StyleRulePage::StyleRulePage):
(WebCore::StyleRulePage::mutableProperties):
(WebCore::StyleRuleFontFace::StyleRuleFontFace):
(WebCore::StyleRuleFontFace::mutableProperties):
(WebCore::StyleRuleViewport::StyleRuleViewport):
(WebCore::StyleRuleViewport::mutableProperties):
(WebCore::StyleRuleFilter::StyleRuleFilter):
(WebCore::StyleRuleFilter::mutableProperties):
* css/ViewportStyleResolver.cpp:
(WebCore::ViewportStyleResolver::addViewportRule):
* css/WebKitCSSKeyframeRule.cpp:
(WebCore::StyleKeyframe::mutableProperties):
* dom/Element.cpp:
(WebCore::UniqueElementData::UniqueElementData):
* dom/StyledElement.cpp:
(WebCore::StyledElement::ensureMutableInlineStyle):
* editing/ApplyStyleCommand.cpp:
(WebCore::copyStyleOrCreateEmpty):
* editing/EditingStyle.cpp:
(WebCore::copyEditingProperties):
(WebCore::editingStyleFromComputedStyle):
(WebCore::EditingStyle::EditingStyle):
(WebCore::EditingStyle::init):
(WebCore::EditingStyle::copy):
(WebCore::EditingStyle::mergeStyle):
(WebCore::getPropertiesNotIn):
* editing/FrameSelection.cpp:
(WebCore::FrameSelection::copyTypingStyle):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148365 268f45cc-cd09-0410-ab3c-d52691b4dbfc