Implement ShadowRoot.delegatesFocus 4/4 (match CSS :focus for shadow host)

Source/core/dom/Node.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2011, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * 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
@@ skipping 342 matching lines @@
     virtual void startLoadingDynamicSheet() { ASSERT_NOT_REACHED(); }
 
     bool hasName() const { ASSERT(!isTextNode()); return getFlag(HasNameOrIsEditingTextFlag); }
 
     bool isUserActionElement() const { return getFlag(IsUserActionElementFlag); }
     void setUserActionElement(bool flag) { setFlag(flag, IsUserActionElementFlag); }
 
     bool active() const { return isUserActionElement() && isUserActionElementActive(); }
     bool inActiveChain() const { return isUserActionElement() && isUserActionElementInActiveChain(); }
     bool hovered() const { return isUserActionElement() && isUserActionElementHovered(); }
+    // Note: As a shadow host whose root with delegatesFocus=false may become focused state when
+    // an inner element gets focused, in that case more than one elements in a document can return
+    // true for |focused()|.  Use Element::isFocusedElementInDocument() or Document::focusedElement()
+    // to check which element is exactly focused.
     bool focused() const { return isUserActionElement() && isUserActionElementFocused(); }
 
     bool needsAttach() const { return styleChangeType() == NeedsReattachStyleChange; }
     bool needsStyleRecalc() const { return styleChangeType() != NoStyleChange; }
     StyleChangeType styleChangeType() const { return static_cast<StyleChangeType>(m_nodeFlags & StyleChangeMask); }
     bool childNeedsStyleRecalc() const { return getFlag(ChildNeedsStyleRecalcFlag); }
     bool isLink() const { return getFlag(IsLinkFlag); }
     bool isEditingText() const { ASSERT(isTextNode()); return getFlag(HasNameOrIsEditingTextFlag); }
 
     void setHasName(bool f) { ASSERT(!isTextNode()); setFlag(f, HasNameOrIsEditingTextFlag); }
@@ skipping 542 matching lines @@
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showNode(const blink::Node*);
 void showTree(const blink::Node*);
 void showNodePath(const blink::Node*);
 #endif
 
 #endif // Node_h