Fix clip-path reference box/coordinate space setup for hit-testing

third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/PaintLayerPainter.h"
 
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/ClipPathClipper.h"
@@ skipping 163 matching lines @@
     paintLayer.setPreviousPaintDirtyRect(paintingInfo.paintDirtyRect);
 
     // Repaint if scroll offset accumulation changes.
     if (!needsRepaint && paintingInfo.scrollOffsetAccumulation != paintLayer.previousScrollOffsetAccumulationForPainting())
         needsRepaint = true;
     paintLayer.setPreviousScrollOffsetAccumulationForPainting(paintingInfo.scrollOffsetAccumulation);
 
     return needsRepaint;
 }
 
-static LayoutRect computeReferenceBox(const LayoutBoxModelObject& boxModelObject)
-{
-    if (boxModelObject.isLayoutInline())
-        return toLayoutInline(boxModelObject).linesBoundingBox();
-    SECURITY_DCHECK(boxModelObject.isBox());
-    return toLayoutBox(boxModelObject).borderBoxRect();
-}
-
 PaintLayerPainter::PaintResult PaintLayerPainter::paintLayerContents(GraphicsContext& context, const PaintLayerPaintingInfo& paintingInfoArg, PaintLayerFlags paintFlags, FragmentPolicy fragmentPolicy)
 {
     ASSERT(m_paintLayer.isSelfPaintingLayer() || m_paintLayer.hasSelfPaintingLayerDescendant());
     ASSERT(!(paintFlags & PaintLayerAppliedTransform));
 
     bool isSelfPaintingLayer = m_paintLayer.isSelfPaintingLayer();
     bool isPaintingOverlayScrollbars = paintFlags & PaintLayerPaintingOverlayScrollbars;
     bool isPaintingScrollingContent = paintFlags & PaintLayerPaintingCompositingScrollingPhase;
     bool isPaintingCompositedForeground = paintFlags & PaintLayerPaintingCompositingForegroundPhase;
     bool isPaintingCompositedBackground = paintFlags & PaintLayerPaintingCompositingBackgroundPhase;
@@ skipping 53 matching lines @@
     Optional<ClipPathClipper> clipPathClipper;
     // Clip-path, like border radius, must not be applied to the contents of a composited-scrolling container.
     // It must, however, still be applied to the mask layer, so that the compositor can properly mask the
     // scrolling contents and scrollbars.
     if (m_paintLayer.layoutObject()->hasClipPath() && (!m_paintLayer.needsCompositedScrolling() || (paintFlags & PaintLayerPaintingChildClippingMaskPhase))) {
         if (!rootRelativeBoundsComputed) {
             rootRelativeBounds = m_paintLayer.physicalBoundingBoxIncludingReflectionAndStackingChildren(offsetFromRoot);
             rootRelativeBoundsComputed = true;
         }
         paintingInfo.ancestorHasClipPathClipping = true;
-        LayoutRect referenceBox(computeReferenceBox(*m_paintLayer.layoutObject()));
+
+        LayoutRect referenceBox(m_paintLayer.boxForClipPath());
         referenceBox.moveBy(offsetFromRoot);
         clipPathClipper.emplace(
             context, *m_paintLayer.layoutObject(), FloatRect(referenceBox), FloatRect(rootRelativeBounds), FloatPoint(offsetFromRoot));
     }
 
     Optional<CompositingRecorder> compositingRecorder;
     // Blending operations must be performed only with the nearest ancestor stacking context.
     // Note that there is no need to composite if we're painting the root.
     // FIXME: this should be unified further into PaintLayer::paintsWithTransparency().
     bool shouldCompositeForBlendMode = (!m_paintLayer.layoutObject()->isDocumentElement() || m_paintLayer.layoutObject()->isSVGRoot()) && m_paintLayer.stackingNode()->isStackingContext() && m_paintLayer.hasNonIsolatedDescendantWithBlendMode();
@@ skipping 489 matching lines @@
     if (!m_paintLayer.containsDirtyOverlayScrollbars())
         return;
 
     PaintLayerPaintingInfo paintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(damageRect)), paintFlags, LayoutSize());
     paintLayer(context, paintingInfo, PaintLayerPaintingOverlayScrollbars);
 
     m_paintLayer.setContainsDirtyOverlayScrollbars(false);
 }
 
 } // namespace blink