Implement a Hit Test Cache.

Source/core/layout/LayoutTableSection.cpp

Index: Source/core/layout/LayoutTableSection.cpp
diff --git a/Source/core/layout/LayoutTableSection.cpp b/Source/core/layout/LayoutTableSection.cpp
index 34c709e8ef2d19ebda472fe4f9cfa77750ce14db..efb4eac5c70b59d09dc155eb77fd9aa6d0032e57 100644
--- a/Source/core/layout/LayoutTableSection.cpp
+++ b/Source/core/layout/LayoutTableSection.cpp
@@ -1528,7 +1528,8 @@ bool LayoutTableSection::nodeAtPoint(HitTestResult& result, const HitTestLocatio
             if (!row->hasSelfPaintingLayer()) {
                 LayoutPoint childPoint = flipForWritingModeForChild(row, adjustedLocation);
                 if (row->nodeAtPoint(result, locationInContainer, childPoint, action)) {
-                    updateHitTestResult(result, toLayoutPoint(locationInContainer.point() - childPoint));
+                    // TODO(dtapuska): Calculate correct box for row.
+                    updateHitTestResult(result, toLayoutPoint(locationInContainer.point() - childPoint), result.validityRect());
                     return true;
                 }
             }
@@ -1559,7 +1560,7 @@ bool LayoutTableSection::nodeAtPoint(HitTestResult& result, const HitTestLocatio
                 LayoutTableCell* cell = current.cells[i];
                 LayoutPoint cellPoint = flipForWritingModeForChild(cell, adjustedLocation);
                 if (static_cast<LayoutObject*>(cell)->nodeAtPoint(result, locationInContainer, cellPoint, action)) {
-                    updateHitTestResult(result, locationInContainer.point() - toLayoutSize(cellPoint));
+                    updateHitTestResult(result, locationInContainer.point() - toLayoutSize(cellPoint), overflowClipRect(adjustedLocation));
                     return true;
                 }
             }