Adds keyboard functionality for videos.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004-2007, 2009, 2014 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 136 matching lines @@
   void CollectStyleForPresentationAttribute(const QualifiedName&,
                                             const AtomicString&,
                                             MutableStylePropertySet*) override;
   unsigned ParseBorderWidthAttribute(const AtomicString&) const;
 
   void ChildrenChanged(const ChildrenChange&) override;
   void CalculateAndAdjustDirectionality();
 
   InsertionNotificationRequest InsertedInto(ContainerNode*) override;
 
+  bool IsSpatialNavigationActive();
+
  private:
   String DebugNodeName() const final;
   String nodeName() const final;
 
   bool IsHTMLElement() const =
       delete;  // This will catch anyone doing an unnecessary check.
   bool IsStyledElement() const =
       delete;  // This will catch anyone doing an unnecessary check.
 
   void MapLanguageAttributeToLocale(const AtomicString&,
@@ skipping 71 matching lines @@
   inline bool IsElementOfType<const thisType>(const HTMLElement& element) {  \
     return Is##thisType(element);                                            \
   }                                                                          \
   DEFINE_ELEMENT_TYPE_CASTS_WITH_FUNCTION(thisType)
 
 }  // namespace blink
 
 #include "core/HTMLElementTypeHelpers.h"
 
 #endif  // HTMLElement_h