EditingStyle: Avoid some unnecessary CSSStyleDeclaration wrappers.
<http://webkit.org/b/114763>

Reviewed by Antti Koivisto.

removeEquivalentProperties(CSSStyleDeclaration) and removeEquivalentProperties(StylePropertySet)
only have different behavior if the CSSStyleDeclaration is computed style (they differ in handling
of the 'font-size' property.)

Avoid creating a CSSStyleDeclaration for StylePropertySets where we can just pass them in directly.

* editing/EditingStyle.cpp:
(WebCore::EditingStyle::removeStyleAddedByNode):
(WebCore::EditingStyle::removeStyleConflictingWithStyleOfNode):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148675 268f45cc-cd09-0410-ab3c-d52691b4dbfc