Introduce "navigation target classification" for spatial navigation

Source/core/page/SpatialNavigation.cpp

 /*
  * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Antonio Gomes <tonikitoo@webkit.org>
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 36 matching lines @@
 
 static RectsAlignment alignmentForRects(FocusType, const LayoutRect&, const LayoutRect&, const LayoutSize& viewSize);
 static bool areRectsFullyAligned(FocusType, const LayoutRect&, const LayoutRect&);
 static bool areRectsPartiallyAligned(FocusType, const LayoutRect&, const LayoutRect&);
 static bool areRectsMoreThanFullScreenApart(FocusType, const LayoutRect& curRect, const LayoutRect& targetRect, const LayoutSize& viewSize);
 static bool isRectInDirection(FocusType, const LayoutRect&, const LayoutRect&);
 static void deflateIfOverlapped(LayoutRect&, LayoutRect&);
 static LayoutRect rectToAbsoluteCoordinates(LocalFrame* initialFrame, const LayoutRect&);
 static bool isScrollableNode(const Node*);
 
-FocusCandidate::FocusCandidate(Node* node, FocusType type)
+FocusCandidate::FocusCandidate(Node* node, FocusType type, NavigationClass targetClass)
     : visibleNode(nullptr)
     , focusableNode(nullptr)
     , enclosingScrollableBox(nullptr)
     , distance(maxDistance())
     , alignment(None)
     , isOffscreen(true)
     , isOffscreenAfterScrolling(true)
+    , targetClass(targetClass)
 {
     ASSERT(node);
     ASSERT(node->isElementNode());
 
     if (isHTMLAreaElement(*node)) {
         HTMLAreaElement& area = toHTMLAreaElement(*node);
         HTMLImageElement* image = area.imageElement();
         if (!image || !image->renderer())
             return;
 
@@ skipping 672 matching lines @@
     LayoutRect rect = virtualRectForDirection(type, rectToAbsoluteCoordinates(area.document().frame(), area.computeRect(area.imageElement()->renderer())), 1);
     return rect;
 }
 
 HTMLFrameOwnerElement* frameOwnerElement(FocusCandidate& candidate)
 {
     return candidate.isFrameOwnerElement() ? toHTMLFrameOwnerElement(candidate.visibleNode) : nullptr;
 };
 
 } // namespace blink