Implement 'sequential focus navigation starting point.'

third_party/WebKit/Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 584 matching lines @@
     void setSelectedStylesheetSet(const String&);
 
     bool setFocusedElement(PassRefPtrWillBeRawPtr<Element>, const FocusParams&);
     void clearFocusedElement();
     Element* focusedElement() const { return m_focusedElement.get(); }
     UserActionElementSet& userActionElements()  { return m_userActionElements; }
     const UserActionElementSet& userActionElements() const { return m_userActionElements; }
     void setNeedsFocusedElementCheck();
     void setAutofocusElement(Element*);
     Element* autofocusElement() const { return m_autofocusElement.get(); }
+    void setSequentialFocusNavigationStartingPoint(Node*);
+    Element* sequentialFocusNavigationStartingPoint(WebFocusType) const;
 
     void setActiveHoverElement(PassRefPtrWillBeRawPtr<Element>);
     Element* activeHoverElement() const { return m_activeHoverElement.get(); }
 
     Node* hoverNode() const { return m_hoverNode.get(); }
 
     void removeFocusedElementOfSubtree(Node*, bool amongChildrenOnly = false);
     void hoveredNodeDetached(Element&);
     void activeChainNodeDetached(Element&);
 
@@ skipping 596 matching lines @@
 
     CompatibilityMode m_compatibilityMode;
     bool m_compatibilityModeLocked; // This is cheaper than making setCompatibilityMode virtual.
 
     OwnPtr<CancellableTaskFactory> m_executeScriptsWaitingForResourcesTask;
 
     bool m_hasAutofocused;
     Timer<Document> m_clearFocusedElementTimer;
     RefPtrWillBeMember<Element> m_autofocusElement;
     RefPtrWillBeMember<Element> m_focusedElement;
+    RefPtrWillBeMember<Range> m_sequentialFocusNavigationStartingPoint;

[sof, 2016/02/25 12:49:54]

Doesn't this risk creating a leak, with the Range keeping a ref-ptr in the other
direction?

     RefPtrWillBeMember<Node> m_hoverNode;
     RefPtrWillBeMember<Element> m_activeHoverElement;
     RefPtrWillBeMember<Element> m_documentElement;
     UserActionElementSet m_userActionElements;
 
     uint64_t m_domTreeVersion;
     static uint64_t s_globalTreeVersion;
 
     uint64_t m_styleVersion;
 
@@ skipping 214 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h