Fix image map focus ring painting

third_party/WebKit/Source/core/html/HTMLAreaElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2008, 2009, 2011 Apple Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 22 matching lines @@
 class HTMLImageElement;
 class Path;
 
 class CORE_EXPORT HTMLAreaElement final : public HTMLAnchorElement {
     DEFINE_WRAPPERTYPEINFO();
 public:
     DECLARE_NODE_FACTORY(HTMLAreaElement);
 
     bool isDefault() const { return m_shape == Default; }
 
-    bool pointInArea(LayoutPoint, const LayoutSize& containerSize);
-
-    LayoutRect computeRect(const LayoutObject*) const;
-    Path computePath(const LayoutObject*) const;
+    // |containerObject| in the following functions is an object (normally a LayoutImage)
+    // which references the containing image map of this area. There might be multiple
+    // objects referencing the same map. For these functions, the effective geometry of
+    // this map will be calculated based on the specified container object, e.g. the
+    // rectangle of the default shape will be the border box rect of the container object,
+    // and effective zoom factor of the container object will be applied on non-default shape.
+    bool pointInArea(const LayoutPoint&, const LayoutObject* containerObject) const;
+    LayoutRect computeAbsoluteRect(const LayoutObject* containerObject) const;
+    Path getPath(const LayoutObject* containerObject) const;
 
     // The parent map's image.
     HTMLImageElement* imageElement() const;
 
 private:
     explicit HTMLAreaElement(Document&);
     ~HTMLAreaElement();
 
     void parseAttribute(const QualifiedName&, const AtomicString&, const AtomicString&) override;
     bool isKeyboardFocusable() const override;
     bool isMouseFocusable() const override;
     bool layoutObjectIsFocusable() const override;
     void updateFocusAppearance(SelectionBehaviorOnFocus) override;
     void setFocus(bool) override;
 
     enum Shape { Default, Poly, Rect, Circle };
-    Path getRegion(const LayoutSize&) const;
-    void invalidateCachedRegion();
+    void invalidateCachedPath();
 
-    OwnPtr<Path> m_region;
+    mutable OwnPtr<Path> m_path;
     Vector<double> m_coords;
-    LayoutSize m_lastSize;
     Shape m_shape;
 };
 
 } // namespace blink
 
 #endif // HTMLAreaElement_h