Relocate box border painting code into BoxBorderPainter

Source/core/paint/BoxPainter.cpp

Index: Source/core/paint/BoxPainter.cpp
diff --git a/Source/core/paint/BoxPainter.cpp b/Source/core/paint/BoxPainter.cpp
index 83ecb5abd8d4154346ddff31205527813becbac5..9982279f618ec95cd4769d5984aa06b4a432e629 100644
--- a/Source/core/paint/BoxPainter.cpp
+++ b/Source/core/paint/BoxPainter.cpp
@@ -19,6 +19,7 @@
 #include "core/style/BorderEdge.h"
 #include "core/style/ShadowList.h"
 #include "core/paint/BackgroundImageGeometry.h"
+#include "core/paint/BoxBorderPainter.h"
 #include "core/paint/BoxDecorationData.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
@@ -1129,101 +1130,6 @@ bool BoxPainter::paintNinePieceImage(LayoutBoxModelObject& obj, GraphicsContext*
     return true;
 }
 
-static FloatRect calculateSideRect(const FloatRoundedRect& outerBorder, const BorderEdge& edge, int side)
-{
-    FloatRect sideRect = outerBorder.rect();
-    int width = edge.width;
-
-    if (side == BSTop)
-        sideRect.setHeight(width);
-    else if (side == BSBottom)
-        sideRect.shiftYEdgeTo(sideRect.maxY() - width);
-    else if (side == BSLeft)
-        sideRect.setWidth(width);
-    else
-        sideRect.shiftXEdgeTo(sideRect.maxX() - width);
-
-    return sideRect;
-}
-
-enum BorderEdgeFlag {
-    TopBorderEdge = 1 << BSTop,
-    RightBorderEdge = 1 << BSRight,
-    BottomBorderEdge = 1 << BSBottom,
-    LeftBorderEdge = 1 << BSLeft,
-    AllBorderEdges = TopBorderEdge | BottomBorderEdge | LeftBorderEdge | RightBorderEdge
-};
-
-static inline BorderEdgeFlag edgeFlagForSide(BoxSide side)
-{
-    return static_cast<BorderEdgeFlag>(1 << side);
-}
-
-static inline bool includesEdge(BorderEdgeFlags flags, BoxSide side)
-{
-    return flags & edgeFlagForSide(side);
-}
-
-inline bool styleRequiresClipPolygon(EBorderStyle style)
-{
-    return style == DOTTED || style == DASHED; // These are drawn with a stroke, so we have to clip to get corner miters.
-}
-
-static bool borderStyleFillsBorderArea(EBorderStyle style)
-{
-    return !(style == DOTTED || style == DASHED || style == DOUBLE);
-}
-
-static bool borderStyleHasInnerDetail(EBorderStyle style)
-{
-    return style == GROOVE || style == RIDGE || style == DOUBLE;
-}
-
-static bool borderStyleIsDottedOrDashed(EBorderStyle style)
-{
-    return style == DOTTED || style == DASHED;
-}
-
-// OUTSET darkens the bottom and right (and maybe lightens the top and left)
-// INSET darkens the top and left (and maybe lightens the bottom and right)
-static inline bool borderStyleHasUnmatchedColorsAtCorner(EBorderStyle style, BoxSide side, BoxSide adjacentSide)
-{
-    // These styles match at the top/left and bottom/right.
-    if (style == INSET || style == GROOVE || style == RIDGE || style == OUTSET) {
-        const BorderEdgeFlags topRightFlags = edgeFlagForSide(BSTop) | edgeFlagForSide(BSRight);
-        const BorderEdgeFlags bottomLeftFlags = edgeFlagForSide(BSBottom) | edgeFlagForSide(BSLeft);
-
-        BorderEdgeFlags flags = edgeFlagForSide(side) | edgeFlagForSide(adjacentSide);
-        return flags == topRightFlags || flags == bottomLeftFlags;
-    }
-    return false;
-}
-
-static inline bool colorsMatchAtCorner(BoxSide side, BoxSide adjacentSide, const BorderEdge edges[])
-{
-    if (edges[side].shouldRender() != edges[adjacentSide].shouldRender())
-        return false;
-
-    if (!edges[side].sharesColorWith(edges[adjacentSide]))
-        return false;
-
-    return !borderStyleHasUnmatchedColorsAtCorner(edges[side].borderStyle(), side, adjacentSide);
-}
-
-static inline bool colorNeedsAntiAliasAtCorner(BoxSide side, BoxSide adjacentSide, const BorderEdge edges[])
-{
-    if (!edges[side].color.hasAlpha())
-        return false;
-
-    if (edges[side].shouldRender() != edges[adjacentSide].shouldRender())
-        return false;
-
-    if (!edges[side].sharesColorWith(edges[adjacentSide]))
-        return true;
-
-    return borderStyleHasUnmatchedColorsAtCorner(edges[side].borderStyle(), side, adjacentSide);
-}
-
 bool BoxPainter::shouldAntialiasLines(GraphicsContext* context)
 {
     // FIXME: We may want to not antialias when scaled by an integral value,
@@ -1233,184 +1139,7 @@ bool BoxPainter::shouldAntialiasLines(GraphicsContext* context)
     return !context->getCTM().isIdentityOrTranslationOrFlipped();
 }
 
-static bool borderWillArcInnerEdge(const FloatSize& firstRadius, const FloatSize& secondRadius)
-{
-    return !firstRadius.isZero() || !secondRadius.isZero();
-}
-
-// This assumes that we draw in order: top, bottom, left, right.
-static inline bool willBeOverdrawn(BoxSide side, BoxSide adjacentSide, const BorderEdge edges[])
-{
-    switch (side) {
-    case BSTop:
-    case BSBottom:
-        if (edges[adjacentSide].presentButInvisible())
-            return false;
-
-        if (!edges[side].sharesColorWith(edges[adjacentSide]) && edges[adjacentSide].color.hasAlpha())
-            return false;
-
-        if (!borderStyleFillsBorderArea(edges[adjacentSide].borderStyle()))
-            return false;
-
-        return true;
-
-    case BSLeft:
-    case BSRight:
-        // These draw last, so are never overdrawn.
-        return false;
-    }
-    return false;
-}
-
-static inline bool borderStylesRequireMitre(BoxSide side, BoxSide adjacentSide, EBorderStyle style, EBorderStyle adjacentStyle)
-{
-    if (style == DOUBLE || adjacentStyle == DOUBLE || adjacentStyle == GROOVE || adjacentStyle == RIDGE)
-        return true;
-
-    if (borderStyleIsDottedOrDashed(style) != borderStyleIsDottedOrDashed(adjacentStyle))
-        return true;
-
-    if (style != adjacentStyle)
-        return true;
-
-    return borderStyleHasUnmatchedColorsAtCorner(style, side, adjacentSide);
-}
-
-static bool joinRequiresMitre(BoxSide side, BoxSide adjacentSide, const BorderEdge edges[], bool allowOverdraw)
-{
-    if ((edges[side].isTransparent && edges[adjacentSide].isTransparent) || !edges[adjacentSide].isPresent)
-        return false;
-
-    if (allowOverdraw && willBeOverdrawn(side, adjacentSide, edges))
-        return false;
-
-    if (!edges[side].sharesColorWith(edges[adjacentSide]))
-        return true;
-
-    if (borderStylesRequireMitre(side, adjacentSide, edges[side].borderStyle(), edges[adjacentSide].borderStyle()))
-        return true;
-
-    return false;
-}
-
-static FloatRect calculateSideRectIncludingInner(const FloatRoundedRect& outerBorder, const BorderEdge edges[], BoxSide side)
-{
-    FloatRect sideRect = outerBorder.rect();
-    int width;
-
-    switch (side) {
-    case BSTop:
-        width = sideRect.height() - edges[BSBottom].width;
-        sideRect.setHeight(width);
-        break;
-    case BSBottom:
-        width = sideRect.height() - edges[BSTop].width;
-        sideRect.shiftYEdgeTo(sideRect.maxY() - width);
-        break;
-    case BSLeft:
-        width = sideRect.width() - edges[BSRight].width;
-        sideRect.setWidth(width);
-        break;
-    case BSRight:
-        width = sideRect.width() - edges[BSLeft].width;
-        sideRect.shiftXEdgeTo(sideRect.maxX() - width);
-        break;
-    }
-
-    return sideRect;
-}
-
-static FloatRoundedRect calculateAdjustedInnerBorder(const FloatRoundedRect& innerBorder, BoxSide side)
-{
-    // Expand the inner border as necessary to make it a rounded rect (i.e. radii contained within each edge).
-    // This function relies on the fact we only get radii not contained within each edge if one of the radii
-    // for an edge is zero, so we can shift the arc towards the zero radius corner.
-    FloatRoundedRect::Radii newRadii = innerBorder.radii();
-    FloatRect newRect = innerBorder.rect();
-
-    float overshoot;
-    float maxRadii;
-
-    switch (side) {
-    case BSTop:
-        overshoot = newRadii.topLeft().width() + newRadii.topRight().width() - newRect.width();
-        // FIXME: once we start pixel-snapping rounded rects after this point, the overshoot concept
-        // should disappear.
-        if (overshoot > 0.1) {
-            newRect.setWidth(newRect.width() + overshoot);
-            if (!newRadii.topLeft().width())
-                newRect.move(-overshoot, 0);
-        }
-        newRadii.setBottomLeft(IntSize(0, 0));
-        newRadii.setBottomRight(IntSize(0, 0));
-        maxRadii = std::max(newRadii.topLeft().height(), newRadii.topRight().height());
-        if (maxRadii > newRect.height())
-            newRect.setHeight(maxRadii);
-        break;
-
-    case BSBottom:
-        overshoot = newRadii.bottomLeft().width() + newRadii.bottomRight().width() - newRect.width();
-        if (overshoot > 0.1) {
-            newRect.setWidth(newRect.width() + overshoot);
-            if (!newRadii.bottomLeft().width())
-                newRect.move(-overshoot, 0);
-        }
-        newRadii.setTopLeft(IntSize(0, 0));
-        newRadii.setTopRight(IntSize(0, 0));
-        maxRadii = std::max(newRadii.bottomLeft().height(), newRadii.bottomRight().height());
-        if (maxRadii > newRect.height()) {
-            newRect.move(0, newRect.height() - maxRadii);
-            newRect.setHeight(maxRadii);
-        }
-        break;
-
-    case BSLeft:
-        overshoot = newRadii.topLeft().height() + newRadii.bottomLeft().height() - newRect.height();
-        if (overshoot > 0.1) {
-            newRect.setHeight(newRect.height() + overshoot);
-            if (!newRadii.topLeft().height())
-                newRect.move(0, -overshoot);
-        }
-        newRadii.setTopRight(IntSize(0, 0));
-        newRadii.setBottomRight(IntSize(0, 0));
-        maxRadii = std::max(newRadii.topLeft().width(), newRadii.bottomLeft().width());
-        if (maxRadii > newRect.width())
-            newRect.setWidth(maxRadii);
-        break;
-
-    case BSRight:
-        overshoot = newRadii.topRight().height() + newRadii.bottomRight().height() - newRect.height();
-        if (overshoot > 0.1) {
-            newRect.setHeight(newRect.height() + overshoot);
-            if (!newRadii.topRight().height())
-                newRect.move(0, -overshoot);
-        }
-        newRadii.setTopLeft(IntSize(0, 0));
-        newRadii.setBottomLeft(IntSize(0, 0));
-        maxRadii = std::max(newRadii.topRight().width(), newRadii.bottomRight().width());
-        if (maxRadii > newRect.width()) {
-            newRect.move(newRect.width() - maxRadii, 0);
-            newRect.setWidth(maxRadii);
-        }
-        break;
-    }
-
-    return FloatRoundedRect(newRect, newRadii);
-}
-
-void BoxPainter::clipBorderSideForComplexInnerPath(GraphicsContext* graphicsContext, const FloatRoundedRect& outerBorder, const FloatRoundedRect& innerBorder,
-    BoxSide side, const BorderEdge edges[])
-{
-    graphicsContext->clip(calculateSideRectIncludingInner(outerBorder, edges, side));
-    FloatRoundedRect adjustedInnerRect = calculateAdjustedInnerBorder(innerBorder, side);
-    if (!adjustedInnerRect.isEmpty())
-        graphicsContext->clipOutRoundedRect(adjustedInnerRect);
-}
-
-namespace {
-
-bool allCornersClippedOut(const FloatRoundedRect& border, const IntRect& intClipRect)
+bool BoxPainter::allCornersClippedOut(const FloatRoundedRect& border, const IntRect& intClipRect)
 {
     LayoutRect boundingRect(border.rect());
     LayoutRect clipRect(intClipRect);
@@ -1442,556 +1171,9 @@ bool allCornersClippedOut(const FloatRoundedRect& border, const IntRect& intClip
     return true;
 }
 
-// TODO(fmalita): Border painting is complex enough to warrant a standalone class. Move all related
-//                logic out into BoxBorderPainter or such.
-// TODO(fmalita): Move static BoxPainter border methods to anonymous ns and update to use a
-//                BoxBorderInfo argument.
-struct BoxBorderInfo {
-    STACK_ALLOCATED();
-public:
-    BoxBorderInfo(const ComputedStyle& style, BackgroundBleedAvoidance bleedAvoidance,
-        bool includeLogicalLeftEdge, bool includeLogicalRightEdge)
-        : style(style)
-        , bleedAvoidance(bleedAvoidance)
-        , includeLogicalLeftEdge(includeLogicalLeftEdge)
-        , includeLogicalRightEdge(includeLogicalRightEdge)
-        , visibleEdgeCount(0)
-        , firstVisibleEdge(0)
-        , visibleEdgeSet(0)
-        , isUniformStyle(true)
-        , isUniformWidth(true)
-        , isUniformColor(true)
-        , hasAlpha(false)
-    {
-
-        style.getBorderEdgeInfo(edges, includeLogicalLeftEdge, includeLogicalRightEdge);
-
-        for (unsigned i = 0; i < WTF_ARRAY_LENGTH(edges); ++i) {
-            const BorderEdge& edge = edges[i];
-
-            if (!edge.shouldRender()) {
-                if (edge.presentButInvisible()) {
-                    isUniformWidth = false;
-                    isUniformColor = false;
-                }
-
-                continue;
-            }
-
-            visibleEdgeCount++;
-            visibleEdgeSet |= edgeFlagForSide(static_cast<BoxSide>(i));
-
-            hasAlpha = hasAlpha || edge.color.hasAlpha();
-
-            if (visibleEdgeCount == 1) {
-                firstVisibleEdge = i;
-                continue;
-            }
-
-            isUniformStyle = isUniformStyle && (edge.borderStyle() == edges[firstVisibleEdge].borderStyle());
-            isUniformWidth = isUniformWidth && (edge.width == edges[firstVisibleEdge].width);
-            isUniformColor = isUniformColor && (edge.color == edges[firstVisibleEdge].color);
-        }
-    }
-
-    const ComputedStyle& style;
-    const BackgroundBleedAvoidance bleedAvoidance;
-    const bool includeLogicalLeftEdge;
-    const bool includeLogicalRightEdge;
-
-    BorderEdge edges[4];
-
-    unsigned visibleEdgeCount;
-    unsigned firstVisibleEdge;
-    BorderEdgeFlags visibleEdgeSet;
-
-    bool isUniformStyle;
-    bool isUniformWidth;
-    bool isUniformColor;
-    bool hasAlpha;
-};
-
-LayoutRectOutsets doubleStripeInsets(const BorderEdge edges[], BorderEdge::DoubleBorderStripe stripe)
-{
-    // Insets are representes as negative outsets.
-    return LayoutRectOutsets(
-        -edges[BSTop].getDoubleBorderStripeWidth(stripe),
-        -edges[BSRight].getDoubleBorderStripeWidth(stripe),
-        -edges[BSBottom].getDoubleBorderStripeWidth(stripe),
-        -edges[BSLeft].getDoubleBorderStripeWidth(stripe));
-}
-
-void drawSolidBorderRect(GraphicsContext* context, const FloatRect& borderRect,
-    float borderWidth, const Color& color)
-{
-    FloatRect strokeRect(borderRect);
-    strokeRect.inflate(-borderWidth / 2);
-
-    bool antialias = BoxPainter::shouldAntialiasLines(context);
-    bool wasAntialias = context->shouldAntialias();
-    if (antialias != wasAntialias)
-        context->setShouldAntialias(antialias);
-
-    context->setStrokeStyle(SolidStroke);
-    context->setStrokeColor(color);
-    context->strokeRect(strokeRect, borderWidth);
-
-    if (antialias != wasAntialias)
-        context->setShouldAntialias(wasAntialias);
-}
-
-void drawBleedAdjustedDRRect(GraphicsContext* context, BackgroundBleedAvoidance bleedAvoidance,
-    const FloatRoundedRect& outer, const FloatRoundedRect& inner, Color color)
-{
-    switch (bleedAvoidance) {
-    case BackgroundBleedBackgroundOverBorder:
-        // BackgroundBleedBackgroundOverBorder draws an opaque background over the inner rrect,
-        // so we can simply fill the outer rect here to avoid backdrop bleeding.
-        context->fillRoundedRect(outer, color);
-        break;
-    case BackgroundBleedClipLayer: {
-        // BackgroundBleedClipLayer clips the outer rrect for the whole layer. Based on this,
-        // we can avoid background bleeding by filling the *outside* of inner rrect, all the
-        // way to the layer bounds (enclosing int rect for the clip, in device space).
-        ASSERT(outer.isRounded());
-
-        SkPath path;
-        path.addRRect(inner);
-        path.setFillType(SkPath::kInverseWinding_FillType);
-
-        SkPaint paint;
-        paint.setColor(color.rgb());
-        paint.setStyle(SkPaint::kFill_Style);
-        paint.setAntiAlias(true);
-        context->drawPath(path, paint);
-
-        break;
-    }
-    case BackgroundBleedClipOnly:
-        if (outer.isRounded()) {
-            // BackgroundBleedClipOnly clips the outer rrect corners for us.
-            FloatRoundedRect adjustedOuter = outer;
-            adjustedOuter.setRadii(FloatRoundedRect::Radii());
-            context->fillDRRect(adjustedOuter, inner, color);
-            break;
-        }
-        // fall through
-    default:
-        context->fillDRRect(outer, inner, color);
-        break;
-    }
-}
-
-void drawDoubleBorder(GraphicsContext* context, const BoxBorderInfo& borderInfo, const LayoutRect& borderRect,
-    const FloatRoundedRect& outerBorder, const FloatRoundedRect& innerBorder)
-{
-    ASSERT(borderInfo.isUniformColor);
-    ASSERT(borderInfo.isUniformStyle);
-    ASSERT(borderInfo.edges[borderInfo.firstVisibleEdge].borderStyle() == DOUBLE);
-    ASSERT(borderInfo.visibleEdgeSet == AllBorderEdges);
-
-    const Color color = borderInfo.edges[borderInfo.firstVisibleEdge].color;
-
-    // outer stripe
-    const LayoutRectOutsets outerThirdInsets =
-        doubleStripeInsets(borderInfo.edges, BorderEdge::DoubleBorderStripeOuter);
-    const FloatRoundedRect outerThirdRect = borderInfo.style.getRoundedInnerBorderFor(borderRect,
-        outerThirdInsets, borderInfo.includeLogicalLeftEdge, borderInfo.includeLogicalRightEdge);
-    drawBleedAdjustedDRRect(context, borderInfo.bleedAvoidance, outerBorder, outerThirdRect, color);
-
-    // inner stripe
-    const LayoutRectOutsets innerThirdInsets =
-        doubleStripeInsets(borderInfo.edges, BorderEdge::DoubleBorderStripeInner);
-    const FloatRoundedRect innerThirdRect = borderInfo.style.getRoundedInnerBorderFor(borderRect,
-        innerThirdInsets, borderInfo.includeLogicalLeftEdge, borderInfo.includeLogicalRightEdge);
-    context->fillDRRect(innerThirdRect, innerBorder, color);
-}
-
-bool paintBorderFastPath(GraphicsContext* context, const BoxBorderInfo& info,
-    const LayoutRect& borderRect, const FloatRoundedRect& outer, const FloatRoundedRect& inner)
-{
-    if (!info.isUniformColor || !info.isUniformStyle || !inner.isRenderable())
-        return false;
-
-    const BorderEdge& firstEdge = info.edges[info.firstVisibleEdge];
-    if (firstEdge.borderStyle() != SOLID && firstEdge.borderStyle() != DOUBLE)
-        return false;
-
-    if (info.visibleEdgeSet == AllBorderEdges) {
-        if (firstEdge.borderStyle() == SOLID) {
-            if (info.isUniformWidth && !outer.isRounded()) {
-                // 4-side, solid, uniform-width, rectangular border => one drawRect()
-                drawSolidBorderRect(context, outer.rect(), firstEdge.width, firstEdge.color);
-            } else {
-                // 4-side, solid border => one drawDRRect()
-                drawBleedAdjustedDRRect(context, info.bleedAvoidance, outer, inner, firstEdge.color);
-            }
-        } else {
-            // 4-side, double border => 2x drawDRRect()
-            ASSERT(firstEdge.borderStyle() == DOUBLE);
-            drawDoubleBorder(context, info, borderRect, outer, inner);
-        }
-
-        return true;
-    }
-
-    // This is faster than the normal complex border path only if it avoids creating transparency
-    // layers (when the border is translucent).
-    if (firstEdge.borderStyle() == SOLID && !outer.isRounded() && info.hasAlpha) {
-        ASSERT(info.visibleEdgeSet != AllBorderEdges);
-        // solid, rectangular border => one drawPath()
-        Path path;
-
-        for (int i = BSTop; i <= BSLeft; ++i) {
-            const BorderEdge& currEdge = info.edges[i];
-            if (currEdge.shouldRender())
-                path.addRect(calculateSideRect(outer, currEdge, i));
-        }
-
-        context->setFillRule(RULE_NONZERO);
-        context->setFillColor(firstEdge.color);
-        context->fillPath(path);
-
-        return true;
-    }
-
-    return false;
-}
-
-} // anonymous namespace
-
 void BoxPainter::paintBorder(LayoutBoxModelObject& obj, const PaintInfo& info, const LayoutRect& rect, const ComputedStyle& style, BackgroundBleedAvoidance bleedAvoidance, bool includeLogicalLeftEdge, bool includeLogicalRightEdge)
 {
-    GraphicsContext* graphicsContext = info.context;
-    // border-image is not affected by border-radius.
-    if (paintNinePieceImage(obj, graphicsContext, rect, style, style.borderImage()))
-        return;
-
-    const BoxBorderInfo borderInfo(style, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
-    FloatRoundedRect outerBorder = style.getRoundedBorderFor(rect, includeLogicalLeftEdge, includeLogicalRightEdge);
-    FloatRoundedRect innerBorder = style.getRoundedInnerBorderFor(rect, includeLogicalLeftEdge, includeLogicalRightEdge);
-
-    if (outerBorder.rect().isEmpty() || !borderInfo.visibleEdgeCount)
-        return;
-
-    const BorderEdge& firstEdge = borderInfo.edges[borderInfo.firstVisibleEdge];
-    bool haveAllSolidEdges = borderInfo.isUniformStyle && firstEdge.borderStyle() == SOLID;
-
-    // If no corner intersects the clip region, we can pretend outerBorder is
-    // rectangular to improve performance.
-    if (haveAllSolidEdges && outerBorder.isRounded() && allCornersClippedOut(outerBorder, info.rect))
-        outerBorder.setRadii(FloatRoundedRect::Radii());
-
-    if (paintBorderFastPath(graphicsContext, borderInfo, rect, outerBorder, innerBorder))
-        return;
-
-    bool clipToOuterBorder = outerBorder.isRounded();
-    GraphicsContextStateSaver stateSaver(*graphicsContext, clipToOuterBorder);
-    if (clipToOuterBorder) {
-        // For BackgroundBleedClip{Only,Layer}, the outer rrect clip is already applied.
-        if (!bleedAvoidanceIsClipping(bleedAvoidance))
-            graphicsContext->clipRoundedRect(outerBorder);
-
-        // For BackgroundBleedBackgroundOverBorder, we're going to draw an opaque background over
-        // the inner rrect - so clipping is not needed (nor desirable due to backdrop bleeding).
-        if (bleedAvoidance != BackgroundBleedBackgroundOverBorder && innerBorder.isRenderable() && !innerBorder.isEmpty())
-            graphicsContext->clipOutRoundedRect(innerBorder);
-    }
-
-    // If only one edge visible antialiasing doesn't create seams
-    bool antialias = shouldAntialiasLines(graphicsContext) || borderInfo.visibleEdgeCount == 1;
-    if (borderInfo.hasAlpha) {
-        paintTranslucentBorderSides(graphicsContext, style, outerBorder, innerBorder, borderInfo.edges,
-        borderInfo.visibleEdgeSet, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias);
-    } else {
-        paintBorderSides(graphicsContext, style, outerBorder, innerBorder, borderInfo.edges,
-        borderInfo.visibleEdgeSet, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias);
-    }
-}
-
-static inline bool includesAdjacentEdges(BorderEdgeFlags flags)
-{
-    // The set includes adjacent edges iff it contains at least one horizontal and one vertical edge.
-    return (flags & (TopBorderEdge | BottomBorderEdge))
-        && (flags & (LeftBorderEdge | RightBorderEdge));
-}
-
-void BoxPainter::paintTranslucentBorderSides(GraphicsContext* graphicsContext, const ComputedStyle& style,
-    const FloatRoundedRect& outerBorder, const FloatRoundedRect& innerBorder, const BorderEdge edges[],
-    BorderEdgeFlags edgesToDraw, BackgroundBleedAvoidance bleedAvoidance, bool includeLogicalLeftEdge,
-    bool includeLogicalRightEdge, bool antialias)
-{
-    // willBeOverdrawn assumes that we draw in order: top, bottom, left, right.
-    // This is different from BoxSide enum order.
-    static const BoxSide paintOrder[] = { BSTop, BSBottom, BSLeft, BSRight };
-
-    while (edgesToDraw) {
-        // Find undrawn edges sharing a color.
-        Color commonColor;
-
-        BorderEdgeFlags commonColorEdgeSet = 0;
-        for (size_t i = 0; i < sizeof(paintOrder) / sizeof(paintOrder[0]); ++i) {
-            BoxSide currSide = paintOrder[i];
-            if (!includesEdge(edgesToDraw, currSide))
-                continue;
-
-            bool includeEdge;
-            if (!commonColorEdgeSet) {
-                commonColor = edges[currSide].color;
-                includeEdge = true;
-            } else {
-                includeEdge = edges[currSide].color == commonColor;
-            }
-
-            if (includeEdge)
-                commonColorEdgeSet |= edgeFlagForSide(currSide);
-        }
-
-        bool useTransparencyLayer = includesAdjacentEdges(commonColorEdgeSet) && commonColor.hasAlpha();
-        if (useTransparencyLayer) {
-            graphicsContext->beginLayer(static_cast<float>(commonColor.alpha()) / 255);
-            commonColor = Color(commonColor.red(), commonColor.green(), commonColor.blue());
-        }
-
-        paintBorderSides(graphicsContext, style, outerBorder, innerBorder, edges, commonColorEdgeSet,
-            bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias, &commonColor);
-
-        if (useTransparencyLayer)
-            graphicsContext->endLayer();
-
-        edgesToDraw &= ~commonColorEdgeSet;
-    }
-}
-
-void BoxPainter::paintOneBorderSide(GraphicsContext* graphicsContext, const ComputedStyle& style, const FloatRoundedRect& outerBorder, const FloatRoundedRect& innerBorder,
-    const FloatRect& sideRect, BoxSide side, BoxSide adjacentSide1, BoxSide adjacentSide2, const BorderEdge edges[], const Path* path,
-    BackgroundBleedAvoidance bleedAvoidance, bool includeLogicalLeftEdge, bool includeLogicalRightEdge, bool antialias, const Color* overrideColor)
-{
-    const BorderEdge& edgeToRender = edges[side];
-    ASSERT(edgeToRender.width);
-    const BorderEdge& adjacentEdge1 = edges[adjacentSide1];
-    const BorderEdge& adjacentEdge2 = edges[adjacentSide2];
-
-    bool mitreAdjacentSide1 = joinRequiresMitre(side, adjacentSide1, edges, !antialias);
-    bool mitreAdjacentSide2 = joinRequiresMitre(side, adjacentSide2, edges, !antialias);
-
-    bool adjacentSide1StylesMatch = colorsMatchAtCorner(side, adjacentSide1, edges);
-    bool adjacentSide2StylesMatch = colorsMatchAtCorner(side, adjacentSide2, edges);
-
-    const Color& colorToPaint = overrideColor ? *overrideColor : edgeToRender.color;
-
-    if (path) {
-        GraphicsContextStateSaver stateSaver(*graphicsContext);
-        if (innerBorder.isRenderable())
-            clipBorderSidePolygon(graphicsContext, outerBorder, innerBorder, side, adjacentSide1StylesMatch, adjacentSide2StylesMatch);
-        else
-            clipBorderSideForComplexInnerPath(graphicsContext, outerBorder, innerBorder, side, edges);
-        float thickness = std::max(std::max(edgeToRender.width, adjacentEdge1.width), adjacentEdge2.width);
-        drawBoxSideFromPath(graphicsContext, LayoutRect(outerBorder.rect()), *path, edges, edgeToRender.width, thickness, side, style,
-            colorToPaint, edgeToRender.borderStyle(), bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
-    } else {
-        bool clipForStyle = styleRequiresClipPolygon(edgeToRender.borderStyle()) && (mitreAdjacentSide1 || mitreAdjacentSide2);
-        bool clipAdjacentSide1 = colorNeedsAntiAliasAtCorner(side, adjacentSide1, edges) && mitreAdjacentSide1;
-        bool clipAdjacentSide2 = colorNeedsAntiAliasAtCorner(side, adjacentSide2, edges) && mitreAdjacentSide2;
-        bool shouldClip = clipForStyle || clipAdjacentSide1 || clipAdjacentSide2;
-
-        GraphicsContextStateSaver clipStateSaver(*graphicsContext, shouldClip);
-        if (shouldClip) {
-            bool aliasAdjacentSide1 = clipAdjacentSide1 || (clipForStyle && mitreAdjacentSide1);
-            bool aliasAdjacentSide2 = clipAdjacentSide2 || (clipForStyle && mitreAdjacentSide2);
-            clipBorderSidePolygon(graphicsContext, outerBorder, innerBorder, side, !aliasAdjacentSide1, !aliasAdjacentSide2);
-            // Since we clipped, no need to draw with a mitre.
-            mitreAdjacentSide1 = false;
-            mitreAdjacentSide2 = false;
-        }
-
-        ObjectPainter::drawLineForBoxSide(graphicsContext, sideRect.x(), sideRect.y(), sideRect.maxX(), sideRect.maxY(), side, colorToPaint, edgeToRender.borderStyle(),
-            mitreAdjacentSide1 ? adjacentEdge1.width : 0, mitreAdjacentSide2 ? adjacentEdge2.width : 0, antialias);
-    }
-}
-
-void BoxPainter::paintBorderSides(GraphicsContext* graphicsContext, const ComputedStyle& style, const FloatRoundedRect& outerBorder, const FloatRoundedRect& innerBorder,
-    const BorderEdge edges[], BorderEdgeFlags edgeSet, BackgroundBleedAvoidance bleedAvoidance,
-    bool includeLogicalLeftEdge, bool includeLogicalRightEdge, bool antialias, const Color* overrideColor)
-{
-    bool renderRadii = outerBorder.isRounded();
-
-    Path roundedPath;
-    if (renderRadii)
-        roundedPath.addRoundedRect(outerBorder);
-
-    // The inner border adjustment for bleed avoidance mode BackgroundBleedBackgroundOverBorder
-    // is only applied to sideRect, which is okay since BackgroundBleedBackgroundOverBorder
-    // is only to be used for solid borders and the shape of the border painted by drawBoxSideFromPath
-    // only depends on sideRect when painting solid borders.
-
-    if (edges[BSTop].shouldRender() && includesEdge(edgeSet, BSTop)) {
-        FloatRect sideRect = outerBorder.rect();
-        sideRect.setHeight(edges[BSTop].width);
-
-        bool usePath = renderRadii && (borderStyleHasInnerDetail(edges[BSTop].borderStyle()) || borderWillArcInnerEdge(innerBorder.radii().topLeft(), innerBorder.radii().topRight()));
-        paintOneBorderSide(graphicsContext, style, outerBorder, innerBorder, sideRect, BSTop, BSLeft, BSRight, edges, usePath ? &roundedPath : 0, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias, overrideColor);
-    }
-
-    if (edges[BSBottom].shouldRender() && includesEdge(edgeSet, BSBottom)) {
-        FloatRect sideRect = outerBorder.rect();
-        sideRect.shiftYEdgeTo(sideRect.maxY() - edges[BSBottom].width);
-
-        bool usePath = renderRadii && (borderStyleHasInnerDetail(edges[BSBottom].borderStyle()) || borderWillArcInnerEdge(innerBorder.radii().bottomLeft(), innerBorder.radii().bottomRight()));
-        paintOneBorderSide(graphicsContext, style, outerBorder, innerBorder, sideRect, BSBottom, BSLeft, BSRight, edges, usePath ? &roundedPath : 0, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias, overrideColor);
-    }
-
-    if (edges[BSLeft].shouldRender() && includesEdge(edgeSet, BSLeft)) {
-        FloatRect sideRect = outerBorder.rect();
-        sideRect.setWidth(edges[BSLeft].width);
-
-        bool usePath = renderRadii && (borderStyleHasInnerDetail(edges[BSLeft].borderStyle()) || borderWillArcInnerEdge(innerBorder.radii().bottomLeft(), innerBorder.radii().topLeft()));
-        paintOneBorderSide(graphicsContext, style, outerBorder, innerBorder, sideRect, BSLeft, BSTop, BSBottom, edges, usePath ? &roundedPath : 0, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias, overrideColor);
-    }
-
-    if (edges[BSRight].shouldRender() && includesEdge(edgeSet, BSRight)) {
-        FloatRect sideRect = outerBorder.rect();
-        sideRect.shiftXEdgeTo(sideRect.maxX() - edges[BSRight].width);
-
-        bool usePath = renderRadii && (borderStyleHasInnerDetail(edges[BSRight].borderStyle()) || borderWillArcInnerEdge(innerBorder.radii().bottomRight(), innerBorder.radii().topRight()));
-        paintOneBorderSide(graphicsContext, style, outerBorder, innerBorder, sideRect, BSRight, BSTop, BSBottom, edges, usePath ? &roundedPath : 0, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge, antialias, overrideColor);
-    }
-}
-
-void BoxPainter::drawBoxSideFromPath(GraphicsContext* graphicsContext, const LayoutRect& borderRect, const Path& borderPath, const BorderEdge edges[],
-    float thickness, float drawThickness, BoxSide side, const ComputedStyle& style, Color color, EBorderStyle borderStyle, BackgroundBleedAvoidance bleedAvoidance,
-    bool includeLogicalLeftEdge, bool includeLogicalRightEdge)
-{
-    if (thickness <= 0)
-        return;
-
-    if (borderStyle == DOUBLE && thickness < 3)
-        borderStyle = SOLID;
-
-    switch (borderStyle) {
-    case BNONE:
-    case BHIDDEN:
-        return;
-    case DOTTED:
-    case DASHED: {
-        graphicsContext->setStrokeColor(color);
-
-        // The stroke is doubled here because the provided path is the
-        // outside edge of the border so half the stroke is clipped off.
-        // The extra multiplier is so that the clipping mask can antialias
-        // the edges to prevent jaggies.
-        graphicsContext->setStrokeThickness(drawThickness * 2 * 1.1f);
-        graphicsContext->setStrokeStyle(borderStyle == DASHED ? DashedStroke : DottedStroke);
-
-        // If the number of dashes that fit in the path is odd and non-integral then we
-        // will have an awkwardly-sized dash at the end of the path. To try to avoid that
-        // here, we simply make the whitespace dashes ever so slightly bigger.
-        // FIXME: This could be even better if we tried to manipulate the dash offset
-        // and possibly the gapLength to get the corners dash-symmetrical.
-        float dashLength = thickness * ((borderStyle == DASHED) ? 3.0f : 1.0f);
-        float gapLength = dashLength;
-        float numberOfDashes = borderPath.length() / dashLength;
-        // Don't try to show dashes if we have less than 2 dashes + 2 gaps.
-        // FIXME: should do this test per side.
-        if (numberOfDashes >= 4) {
-            bool evenNumberOfFullDashes = !((int)numberOfDashes % 2);
-            bool integralNumberOfDashes = !(numberOfDashes - (int)numberOfDashes);
-            if (!evenNumberOfFullDashes && !integralNumberOfDashes) {
-                float numberOfGaps = numberOfDashes / 2;
-                gapLength += (dashLength  / numberOfGaps);
-            }
-
-            DashArray lineDash;
-            lineDash.append(dashLength);
-            lineDash.append(gapLength);
-            graphicsContext->setLineDash(lineDash, dashLength);
-        }
-
-        // FIXME: stroking the border path causes issues with tight corners:
-        // https://bugs.webkit.org/show_bug.cgi?id=58711
-        // Also, to get the best appearance we should stroke a path between the two borders.
-        graphicsContext->strokePath(borderPath);
-        return;
-    }
-    case DOUBLE: {
-        // Draw inner border line
-        {
-            GraphicsContextStateSaver stateSaver(*graphicsContext);
-            const LayoutRectOutsets innerInsets = doubleStripeInsets(edges, BorderEdge::DoubleBorderStripeInner);
-            FloatRoundedRect innerClip = style.getRoundedInnerBorderFor(borderRect,
-                innerInsets, includeLogicalLeftEdge, includeLogicalRightEdge);
-
-            graphicsContext->clipRoundedRect(innerClip);
-            drawBoxSideFromPath(graphicsContext, borderRect, borderPath, edges, thickness, drawThickness, side, style, color, SOLID, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
-        }
-
-        // Draw outer border line
-        {
-            GraphicsContextStateSaver stateSaver(*graphicsContext);
-            LayoutRect outerRect = borderRect;
-            LayoutRectOutsets outerInsets = doubleStripeInsets(edges, BorderEdge::DoubleBorderStripeOuter);
-
-            if (bleedAvoidanceIsClipping(bleedAvoidance)) {
-                outerRect.inflate(1);
-                outerInsets.setTop(outerInsets.top() - 1);
-                outerInsets.setRight(outerInsets.right() - 1);
-                outerInsets.setBottom(outerInsets.bottom() - 1);
-                outerInsets.setLeft(outerInsets.left() - 1);
-            }
-
-            FloatRoundedRect outerClip = style.getRoundedInnerBorderFor(outerRect, outerInsets,
-                includeLogicalLeftEdge, includeLogicalRightEdge);
-            graphicsContext->clipOutRoundedRect(outerClip);
-            drawBoxSideFromPath(graphicsContext, borderRect, borderPath, edges, thickness, drawThickness, side, style, color, SOLID, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
-        }
-        return;
-    }
-    case RIDGE:
-    case GROOVE:
-    {
-        EBorderStyle s1;
-        EBorderStyle s2;
-        if (borderStyle == GROOVE) {
-            s1 = INSET;
-            s2 = OUTSET;
-        } else {
-            s1 = OUTSET;
-            s2 = INSET;
-        }
-
-        // Paint full border
-        drawBoxSideFromPath(graphicsContext, borderRect, borderPath, edges, thickness, drawThickness, side, style, color, s1, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
-
-        // Paint inner only
-        GraphicsContextStateSaver stateSaver(*graphicsContext);
-        LayoutUnit topWidth = edges[BSTop].usedWidth() / 2;
-        LayoutUnit bottomWidth = edges[BSBottom].usedWidth() / 2;
-        LayoutUnit leftWidth = edges[BSLeft].usedWidth() / 2;
-        LayoutUnit rightWidth = edges[BSRight].usedWidth() / 2;
-
-        FloatRoundedRect clipRect = style.getRoundedInnerBorderFor(borderRect,
-            LayoutRectOutsets(-topWidth, -rightWidth, -bottomWidth, -leftWidth),
-            includeLogicalLeftEdge, includeLogicalRightEdge);
-
-        graphicsContext->clipRoundedRect(clipRect);
-        drawBoxSideFromPath(graphicsContext, borderRect, borderPath, edges, thickness, drawThickness, side, style, color, s2, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
-        return;
-    }
-    case INSET:
-        if (side == BSTop || side == BSLeft)
-            color = color.dark();
-        break;
-    case OUTSET:
-        if (side == BSBottom || side == BSRight)
-            color = color.dark();
-        break;
-    default:
-        break;
-    }
-
-    graphicsContext->setStrokeStyle(NoStroke);
-    graphicsContext->setFillColor(color);
-    graphicsContext->drawRect(pixelSnappedIntRect(borderRect));
+    BoxBorderPainter().paintBorder(obj, info, rect, style, bleedAvoidance, includeLogicalLeftEdge, includeLogicalRightEdge);
 }
 
 void BoxPainter::paintBoxShadow(const PaintInfo& info, const LayoutRect& paintRect, const ComputedStyle& style, ShadowStyle shadowStyle, bool includeLogicalLeftEdge, bool includeLogicalRightEdge)
@@ -2117,190 +1299,4 @@ void BoxPainter::paintBoxShadow(const PaintInfo& info, const LayoutRect& paintRe
     }
 }
 
-void BoxPainter::clipBorderSidePolygon(GraphicsContext* graphicsContext, const FloatRoundedRect& outerBorder, const FloatRoundedRect& innerBorder, BoxSide side, bool firstEdgeMatches, bool secondEdgeMatches)
-{
-    FloatPoint quad[4];
-
-    const LayoutRect outerRect(outerBorder.rect());
-    const LayoutRect innerRect(innerBorder.rect());
-
-    FloatPoint centerPoint(innerRect.location().x().toFloat() + innerRect.width().toFloat() / 2, innerRect.location().y().toFloat() + innerRect.height().toFloat() / 2);
-
-    // For each side, create a quad that encompasses all parts of that side that may draw,
-    // including areas inside the innerBorder.
-    //
-    //         0----------------3
-    //       0  \              /  0
-    //       |\  1----------- 2  /|
-    //       | 1                1 |
-    //       | |                | |
-    //       | |                | |
-    //       | 2                2 |
-    //       |/  1------------2  \|
-    //       3  /              \  3
-    //         0----------------3
-    //
-    switch (side) {
-    case BSTop:
-        quad[0] = FloatPoint(outerRect.minXMinYCorner());
-        quad[1] = FloatPoint(innerRect.minXMinYCorner());
-        quad[2] = FloatPoint(innerRect.maxXMinYCorner());
-        quad[3] = FloatPoint(outerRect.maxXMinYCorner());
-
-        if (!innerBorder.radii().topLeft().isZero()) {
-            findIntersection(quad[0], quad[1],
-                FloatPoint(
-                    quad[1].x() + innerBorder.radii().topLeft().width(),
-                    quad[1].y()),
-                FloatPoint(
-                    quad[1].x(),
-                    quad[1].y() + innerBorder.radii().topLeft().height()),
-                quad[1]);
-        }
-
-        if (!innerBorder.radii().topRight().isZero()) {
-            findIntersection(quad[3], quad[2],
-                FloatPoint(
-                    quad[2].x() - innerBorder.radii().topRight().width(),
-                    quad[2].y()),
-                FloatPoint(
-                    quad[2].x(),
-                    quad[2].y() + innerBorder.radii().topRight().height()),
-                quad[2]);
-        }
-        break;
-
-    case BSLeft:
-        quad[0] = FloatPoint(outerRect.minXMinYCorner());
-        quad[1] = FloatPoint(innerRect.minXMinYCorner());
-        quad[2] = FloatPoint(innerRect.minXMaxYCorner());
-        quad[3] = FloatPoint(outerRect.minXMaxYCorner());
-
-        if (!innerBorder.radii().topLeft().isZero()) {
-            findIntersection(quad[0], quad[1],
-                FloatPoint(
-                    quad[1].x() + innerBorder.radii().topLeft().width(),
-                    quad[1].y()),
-                FloatPoint(
-                    quad[1].x(),
-                    quad[1].y() + innerBorder.radii().topLeft().height()),
-                quad[1]);
-        }
-
-        if (!innerBorder.radii().bottomLeft().isZero()) {
-            findIntersection(quad[3], quad[2],
-                FloatPoint(
-                    quad[2].x() + innerBorder.radii().bottomLeft().width(),
-                    quad[2].y()),
-                FloatPoint(
-                    quad[2].x(),
-                    quad[2].y() - innerBorder.radii().bottomLeft().height()),
-                quad[2]);
-        }
-        break;
-
-    case BSBottom:
-        quad[0] = FloatPoint(outerRect.minXMaxYCorner());
-        quad[1] = FloatPoint(innerRect.minXMaxYCorner());
-        quad[2] = FloatPoint(innerRect.maxXMaxYCorner());
-        quad[3] = FloatPoint(outerRect.maxXMaxYCorner());
-
-        if (!innerBorder.radii().bottomLeft().isZero()) {
-            findIntersection(quad[0], quad[1],
-                FloatPoint(
-                    quad[1].x() + innerBorder.radii().bottomLeft().width(),
-                    quad[1].y()),
-                FloatPoint(
-                    quad[1].x(),
-                    quad[1].y() - innerBorder.radii().bottomLeft().height()),
-                quad[1]);
-        }
-
-        if (!innerBorder.radii().bottomRight().isZero()) {
-            findIntersection(quad[3], quad[2],
-                FloatPoint(
-                    quad[2].x() - innerBorder.radii().bottomRight().width(),
-                    quad[2].y()),
-                FloatPoint(
-                    quad[2].x(),
-                    quad[2].y() - innerBorder.radii().bottomRight().height()),
-                quad[2]);
-        }
-        break;
-
-    case BSRight:
-        quad[0] = FloatPoint(outerRect.maxXMinYCorner());
-        quad[1] = FloatPoint(innerRect.maxXMinYCorner());
-        quad[2] = FloatPoint(innerRect.maxXMaxYCorner());
-        quad[3] = FloatPoint(outerRect.maxXMaxYCorner());
-
-        if (!innerBorder.radii().topRight().isZero()) {
-            findIntersection(quad[0], quad[1],
-                FloatPoint(
-                    quad[1].x() - innerBorder.radii().topRight().width(),
-                    quad[1].y()),
-                FloatPoint(
-                    quad[1].x(),
-                    quad[1].y() + innerBorder.radii().topRight().height()),
-                quad[1]);
-        }
-
-        if (!innerBorder.radii().bottomRight().isZero()) {
-            findIntersection(quad[3], quad[2],
-                FloatPoint(
-                    quad[2].x() - innerBorder.radii().bottomRight().width(),
-                    quad[2].y()),
-                FloatPoint(
-                    quad[2].x(),
-                    quad[2].y() - innerBorder.radii().bottomRight().height()),
-                quad[2]);
-        }
-        break;
-    }
-
-    // If the border matches both of its adjacent sides, don't anti-alias the clip, and
-    // if neither side matches, anti-alias the clip.
-    if (firstEdgeMatches == secondEdgeMatches) {
-        graphicsContext->clipPolygon(4, quad, !firstEdgeMatches);
-        return;
-    }
-
-    // If antialiasing settings for the first edge and second edge is different,
-    // they have to be addressed separately. We do this by breaking the quad into
-    // two parallelograms, made by moving quad[1] and quad[2].
-    float ax = quad[1].x() - quad[0].x();
-    float ay = quad[1].y() - quad[0].y();
-    float bx = quad[2].x() - quad[1].x();
-    float by = quad[2].y() - quad[1].y();
-    float cx = quad[3].x() - quad[2].x();
-    float cy = quad[3].y() - quad[2].y();
-
-    const static float kEpsilon = 1e-2f;
-    float r1, r2;
-    if (fabsf(bx) < kEpsilon && fabsf(by) < kEpsilon) {
-        // The quad was actually a triangle.
-        r1 = r2 = 1.0f;
-    } else {
-        // Extend parallelogram a bit to hide calculation error
-        const static float kExtendFill = 1e-2f;
-
-        r1 = (-ax * by + ay * bx) / (cx * by - cy * bx) + kExtendFill;
-        r2 = (-cx * by + cy * bx) / (ax * by - ay * bx) + kExtendFill;
-    }
-
-    FloatPoint firstQuad[4];
-    firstQuad[0] = quad[0];
-    firstQuad[1] = quad[1];
-    firstQuad[2] = FloatPoint(quad[3].x() + r2 * ax, quad[3].y() + r2 * ay);
-    firstQuad[3] = quad[3];
-    graphicsContext->clipPolygon(4, firstQuad, !firstEdgeMatches);
-
-    FloatPoint secondQuad[4];
-    secondQuad[0] = quad[0];
-    secondQuad[1] = FloatPoint(quad[0].x() - r1 * cx, quad[0].y() - r1 * cy);
-    secondQuad[2] = quad[2];
-    secondQuad[3] = quad[3];
-    graphicsContext->clipPolygon(4, secondQuad, !secondEdgeMatches);
-}
-
 } // namespace blink