Reviewed by Eric.
        
        https://bugs.webkit.org/show_bug.cgi?id=12438

        More SVG animation:
        
        - Make multiple additive animations work
        - Support animating <use> instance trees

        * svg/SVGAnimateColorElement.cpp:
        (WebCore::SVGAnimateColorElement::SVGAnimateColorElement):
        * svg/SVGAnimateColorElement.h:
        
        Made this AnimateElement subclass. All functionality is now provided by AnimateElement.
        
        * svg/SVGAnimateElement.cpp:
        (WebCore::SVGAnimateElement::determinePropertyType):
        (WebCore::SVGAnimateElement::calculateAnimatedValue):
        (WebCore::SVGAnimateElement::calculateFromAndToValues):
        (WebCore::SVGAnimateElement::calculateFromAndByValues):
        (WebCore::SVGAnimateElement::resetToBaseValue):
        (WebCore::SVGAnimateElement::applyResultsToTarget):
        * svg/SVGAnimateElement.h:
        * svg/SVGAnimateMotionElement.cpp:
        (WebCore::SVGAnimateMotionElement::resetToBaseValue):
        (WebCore::SVGAnimateMotionElement::calculateAnimatedValue):
        (WebCore::SVGAnimateMotionElement::applyResultsToTarget):
        * svg/SVGAnimateMotionElement.h:
        * svg/SVGAnimateTransformElement.cpp:
        (WebCore::SVGAnimateTransformElement::resetToBaseValue):
        (WebCore::SVGAnimateTransformElement::calculateAnimatedValue):
        (WebCore::SVGAnimateTransformElement::calculateFromAndByValues):
        (WebCore::SVGAnimateTransformElement::applyResultsToTarget):
        * svg/SVGAnimateTransformElement.h:
        
        Switch to new model where
        - resetToBaseValue() resets the animated value back to the base value
        - calculateAnimatedValue() computes the value and adds it to the element used for accumulation
        - applyResultsToTarget() sets the computed value the target element
        
        * svg/SVGAnimationElement.cpp:
        (WebCore::SVGAnimationElement::fromValue):
        (WebCore::SVGAnimationElement::attributeIsCSS):
        (WebCore::SVGAnimationElement::targetAttributeIsCSS):
        (WebCore::SVGAnimationElement::setTargetAttributeAnimatedValue):
        
        Update instances too.
        
        (WebCore::SVGAnimationElement::startedActiveInterval):
        (WebCore::SVGAnimationElement::updateAnimation):
        (WebCore::SVGAnimationElement::endedActiveInterval):
        * svg/SVGAnimationElement.h:
        * svg/SVGSVGElement.cpp:
        (WebCore::SVGSVGElement::SVGSVGElement):
        * svg/SVGSetElement.cpp:
        (WebCore::SVGSetElement::SVGSetElement):
        * svg/SVGSetElement.h:
        
        Made this AnimateElement subclass. All functionality is now provided by AnimateElement.
        
        * svg/animation/SMILTimeContainer.cpp:
        (WebCore::SMILTimeContainer::SMILTimeContainer):
        (WebCore::SMILTimeContainer::unschedule):
        (WebCore::SMILTimeContainer::updateDocumentOrderIndexes):
        (WebCore::PriorityCompare::PriorityCompare):
        (WebCore::PriorityCompare::operator()):
        (WebCore::SMILTimeContainer::sortByPriority):
        (WebCore::applyOrderSortFunction):
        (WebCore::sortByApplyOrder):
        (WebCore::SMILTimeContainer::baseValueFor):
        (WebCore::SMILTimeContainer::updateAnimations):
        * svg/animation/SMILTimeContainer.h:
        (WebCore::SMILTimeContainer::create):
        (WebCore::SMILTimeContainer::setDocumentOrderIndexesDirty):
        
        Do additive animation with the following steps
        - sort active animations based on their priority (begin time, document order).
        - if not yet saved for each (element, attribute) pair save the base value.
        - lowest priority animation for each (element, attribute) acts as the result element.
        - animation results are resolved in priority order and results are accumulated to the result element.
        - after all active animations have been processed the values in result elements are applied to the target elements.
        
        * svg/animation/SVGSMILElement.cpp:
        (WebCore::SVGSMILElement::SVGSMILElement):
        (WebCore::SVGSMILElement::insertedIntoDocument):
        
        Invalidate document order index.
        
        (WebCore::SVGSMILElement::attributeName):
        (WebCore::SVGSMILElement::isInactive):
        (WebCore::SVGSMILElement::isFrozen):
        (WebCore::SVGSMILElement::beginListChanged):
        (WebCore::SVGSMILElement::determineActiveState):
        (WebCore::SVGSMILElement::isContributing):
        (WebCore::SVGSMILElement::progress):
        
        Take care that animations in frozen state still contribute to the total. Since we now build the result starting
        from the base value, fill="replace" works magically simply by not contributing anything.
        
        * svg/animation/SVGSMILElement.h:
        (WebCore::SVGSMILElement::previousIntervalBegin):
        (WebCore::SVGSMILElement::documentOrderIndex):
        (WebCore::SVGSMILElement::setDocumentOrderIndex):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@32044 268f45cc-cd09-0410-ab3c-d52691b4dbfc