WIP (Introduce WTF::NonNullPtr<T>.)

Source/core/page/FocusController.h

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 11 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef FocusController_h
 #define FocusController_h
 
 #include "core/page/FocusDirection.h"
 #include "core/platform/graphics/LayoutRect.h"
 #include "wtf/Forward.h"
+#include "wtf/NonNullPtr.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 struct FocusCandidate;
 class Document;
 class Element;
 class Frame;
 class HTMLFrameOwnerElement;
 class HTMLShadowElement;
 class IntRect;
 class KeyboardEvent;
 class Node;
 class Page;
 class TreeScope;
 
 class FocusNavigationScope {
 public:
     Node* rootNode() const;
     Element* owner() const;
     static FocusNavigationScope focusNavigationScopeOf(Node*);
     static FocusNavigationScope ownedByNonFocusableFocusScopeOwner(Node*);
     static FocusNavigationScope ownedByShadowHost(Node*);
     static FocusNavigationScope ownedByShadowInsertionPoint(HTMLShadowElement*);
     static FocusNavigationScope ownedByIFrame(HTMLFrameOwnerElement*);
 
 private:
-    explicit FocusNavigationScope(TreeScope*);
-    TreeScope* m_rootTreeScope;
+    explicit FocusNavigationScope(NonNullPtr<TreeScope>);
+    NonNullPtr<TreeScope> m_rootTreeScope;
 };
 
 class FocusController {
     WTF_MAKE_NONCOPYABLE(FocusController); WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<FocusController> create(Page*);
 
     void setFocusedFrame(PassRefPtr<Frame>);
     Frame* focusedFrame() const { return m_focusedFrame.get(); }
     Frame* focusedOrMainFrame() const;
@@ skipping 47 matching lines @@
     bool m_isActive;
     bool m_isFocused;
     bool m_isChangingFocusedFrame;
     bool m_containingWindowIsVisible;
 
 };
 
 } // namespace WebCore
 
 #endif // FocusController_h