Implement a Hit Test Cache.

Source/core/layout/LayoutTable.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1322 matching lines @@
 bool LayoutTable::nodeAtPoint(HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
 {
     LayoutPoint adjustedLocation = accumulatedOffset + location();
 
     // Check kids first.
     if (!hasOverflowClip() || locationInContainer.intersects(overflowClipRect(adjustedLocation))) {
         for (LayoutObject* child = lastChild(); child; child = child->previousSibling()) {
             if (child->isBox() && !toLayoutBox(child)->hasSelfPaintingLayer() && (child->isTableSection() || child->isTableCaption())) {
                 LayoutPoint childPoint = flipForWritingModeForChild(toLayoutBox(child), adjustedLocation);
                 if (child->nodeAtPoint(result, locationInContainer, childPoint, action)) {
-                    updateHitTestResult(result, toLayoutPoint(locationInContainer.point() - childPoint));
+                    // TODO(dtapuska): Calculate child's rect
+                    updateHitTestResult(result, toLayoutPoint(locationInContainer.point() - childPoint), result.validityRect());
                     return true;
                 }
             }
         }
     }
 
     // Check our bounds next.
     LayoutRect boundsRect(adjustedLocation, size());
     if (visibleToHitTestRequest(result.hitTestRequest()) && (action == HitTestBlockBackground || action == HitTestChildBlockBackground) && locationInContainer.intersects(boundsRect)) {
-        updateHitTestResult(result, flipForWritingMode(locationInContainer.point() - toLayoutSize(adjustedLocation)));
+        updateHitTestResult(result, flipForWritingMode(locationInContainer.point() - toLayoutSize(adjustedLocation)), boundsRect);
         if (!result.addNodeToListBasedTestResult(node(), locationInContainer, boundsRect))
             return true;
     }
-
+    result.shrinkValidityRect(boundsRect);
     return false;
 }
 
 LayoutTable* LayoutTable::createAnonymousWithParent(const LayoutObject* parent)
 {
     RefPtr<ComputedStyle> newStyle = ComputedStyle::createAnonymousStyleWithDisplay(parent->styleRef(), TABLE);
     LayoutTable* newTable = new LayoutTable(0);
     newTable->setDocumentForAnonymous(&parent->document());
     newTable->setStyle(newStyle.release());
     return newTable;
@@ skipping 37 matching lines @@
                         cell->invalidateDisplayItemClient(*cell);
                 }
             }
         }
     }
 
     LayoutBlock::invalidatePaintOfSubtreesIfNeeded(childPaintInvalidationState);
 }
 
 }