Reviewed by James Robinson.

        Incorporate algorithm for processing paths into GPU-renderable triangle meshes
        https://bugs.webkit.org/show_bug.cgi?id=45521

        Adding an implementation of Loop and Blinn's GPU accelerated path
        rendering algorithm from GPU Gems 3. This implementation pays
        particular attention to the efficiency of the curve subdivision
        phase needed for correct rendering. It utilizes the OpenGL utility
        library tessellator for triangulation of the interior of the
        shape. The regions handled by Loop and Blinn's algorithm are
        handled by the local triangulator previously incorporated.

        No tests yet; pixel tests will eventually be used to verify this
        algorithm and prevent regressions.

        * platform/graphics/gpu/LoopBlinnPathProcessor.cpp: Added.
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::Segment):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::setup):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::kind):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::getPoint):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::next):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::prev):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::setNext):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::setPrev):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::contour):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::subdivide):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::boundingBox):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::numCrossingsForXRay):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::numberOfTriangles):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::getTriangle):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::numberOfInteriorVertices):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::getInteriorVertex):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::markedForSubdivision):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::setMarkedForSubdivision):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::toString):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::computeBoundingBox):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::Contour):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::add):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::subdivide):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::begin):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::end):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::isOrientedCounterClockwise):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::setIsOrientedCounterClockwise):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::boundingBox):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::fillSide):
        (WebCore::LoopBlinnPathProcessorImplementation::Contour::setFillSide):
        (WebCore::LoopBlinnPathProcessorImplementation::Segment::triangulate):
        (WebCore::LoopBlinnPathProcessor::LoopBlinnPathProcessor):
        (WebCore::LoopBlinnPathProcessor::~LoopBlinnPathProcessor):
        (WebCore::LoopBlinnPathProcessor::process):
        (WebCore::LoopBlinnPathProcessor::buildContours):
        (WebCore::LoopBlinnPathProcessor::allSegmentsOverlappingY):
        (WebCore::LoopBlinnPathProcessor::determineSidesToFill):
        (WebCore::LoopBlinnPathProcessor::determineOrientation):
        (WebCore::SweepData::SweepEvent::SweepEvent):
        (WebCore::SweepData::SweepEvent::setup):
        (WebCore::SweepData::SweepEvent::x):
        (WebCore::SweepData::SweepEvent::entry):
        (WebCore::SweepData::SweepEvent::interval):
        (WebCore::SweepData::SweepEvent::operator<):
        (WebCore::SweepData::trianglesOverlap):
        (WebCore::LoopBlinnPathProcessor::subdivideCurves):
        (WebCore::LoopBlinnPathProcessor::conditionallySubdivide):
        (WebCore::LoopBlinnPathProcessor::subdivideCurvesSlow):
        (WebCore::TessellationState::vertexCallback):
        (WebCore::TessellationState::combineCallback):
        (WebCore::TessellationState::edgeFlagCallback):
        (WebCore::LoopBlinnPathProcessor::tessellateInterior):
        * platform/graphics/gpu/LoopBlinnPathProcessor.h: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@78264 268f45cc-cd09-0410-ab3c-d52691b4dbfc