Implement a Hit Test Cache.

Source/core/layout/svg/LayoutSVGRoot.cpp

 /*
  * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2007, 2008, 2009 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 378 matching lines @@
     // don't clip to the viewport, the visual overflow rect.
     // FIXME: This should be an intersection when rect-based hit tests are supported by nodeAtFloatPoint.
     if (contentBoxRect().contains(pointInBorderBox) || (!shouldApplyViewportClip() && visualOverflowRect().contains(pointInBorderBox))) {
         const AffineTransform& localToParentTransform = this->localToParentTransform();
         if (localToParentTransform.isInvertible()) {
             FloatPoint localPoint = localToParentTransform.inverse().mapPoint(FloatPoint(pointInParent));
 
             for (LayoutObject* child = lastChild(); child; child = child->previousSibling()) {
                 // FIXME: nodeAtFloatPoint() doesn't handle rect-based hit tests yet.
                 if (child->nodeAtFloatPoint(result, localPoint, hitTestAction)) {
-                    updateHitTestResult(result, pointInBorderBox);
+                    updateHitTestResult(result, pointInBorderBox, boundingRect(locationInContainer.point()));
                     if (!result.addNodeToListBasedTestResult(child->node(), locationInContainer))
                         return true;
                 }
             }
         }
     }
 
     // If we didn't early exit above, we've just hit the container <svg> element. Unlike SVG 1.1, 2nd Edition allows container elements to be hit.
     if ((hitTestAction == HitTestBlockBackground || hitTestAction == HitTestChildBlockBackground) && visibleToHitTestRequest(result.hitTestRequest())) {
         // Only return true here, if the last hit testing phase 'BlockBackground' (or 'ChildBlockBackground' - depending on context) is executed.
         // If we'd return true in the 'Foreground' phase, hit testing would stop immediately. For SVG only trees this doesn't matter.
         // Though when we have a <foreignObject> subtree we need to be able to detect hits on the background of a <div> element.
         // If we'd return true here in the 'Foreground' phase, we are not able to detect these hits anymore.
         LayoutRect boundsRect(accumulatedOffset + location(), size());
         if (locationInContainer.intersects(boundsRect)) {
-            updateHitTestResult(result, pointInBorderBox);
+            updateHitTestResult(result, pointInBorderBox, boundsRect);
             if (!result.addNodeToListBasedTestResult(node(), locationInContainer, boundsRect))
                 return true;
         }
     }
 
     return false;
 }
 
 }