Revert of Remove FrameView::Root

third_party/WebKit/Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
    reserved.
 
    This library is free software; you can redistribute it and/or
@@ skipping 480 matching lines @@
   bool IsParentVisible() const {
     return parent_visible_;
   }  // Whether or not our parent is visible.
   bool IsVisible() const {
     return self_visible_ && parent_visible_;
   }  // Whether or not we are actually visible.
   void SetParentVisible(bool);
   void SetSelfVisible(bool v) { self_visible_ = v; }
   void SetParent(FrameViewBase*) override;
   FrameViewBase* Parent() const override { return parent_; }
+  FrameView* Root() const;
   void RemoveChild(FrameViewBase*);
   void AddChild(FrameViewBase*);
   const ChildrenSet* Children() const { return &children_; }
   void RemovePlugin(PluginView*);
   void AddPlugin(PluginView*);
   const PluginsSet* Plugins() const { return &plugins_; }
   void RemoveScrollbar(Scrollbar*);
   void AddScrollbar(Scrollbar*);
   const ScrollbarsSet* Scrollbars() const { return &scrollbars_; }
 
@@ skipping 763 matching lines @@
                   frameViewBase.IsFrameView());
 DEFINE_TYPE_CASTS(FrameView,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->IsFrameView(),
                   scrollableArea.IsFrameView());
 
 }  // namespace blink
 
 #endif  // FrameView_h