[Layout API] Start converting ScrollAnchor to new layout API

third_party/WebKit/Source/core/layout/api/LayoutBoxItem.h

 // Copyright 2016 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.
 
 #ifndef LayoutBoxItem_h
 #define LayoutBoxItem_h
 
 #include "core/layout/LayoutBox.h"
 #include "core/layout/api/LayoutBoxModel.h"
 #include "platform/scroll/ScrollTypes.h"
@@ skipping 39 matching lines @@
     LayoutPoint location() const
     {
         return toBox()->location();
     }
 
     LayoutUnit minPreferredLogicalWidth() const
     {
         return toBox()->minPreferredLogicalWidth();
     }
 
+    LayoutRect overflowClipRect(const LayoutPoint& location, OverlayScrollbarClipBehavior behavior = IgnoreOverlayScrollbarSize) const
+    {
+        return toBox()->overflowClipRect(location, behavior);
+    }
+
 private:
     LayoutBox* toBox()
     {
         return toLayoutBox(layoutObject());
     }
 
     const LayoutBox* toBox() const
     {
         return toLayoutBox(layoutObject());
     }
 };
 
 } // namespace blink
 
 #endif // LayoutBoxItem_h