Replace forward class declarations of VisiblePosition to include directives

Source/core/editing/commands/FormatBlockCommand.h

 /*
  * Copyright (C) 2006, 2008 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 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (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 FormatBlockCommand_h
 #define FormatBlockCommand_h
 
 #include "core/dom/QualifiedName.h"
 #include "core/editing/Position.h"
+#include "core/editing/VisiblePosition.h"
 #include "core/editing/commands/ApplyBlockElementCommand.h"
 #include "core/editing/commands/EditAction.h"
 
 namespace blink {
 
 class Document;
 class Element;
 class Range;
-class VisiblePosition;
 
 class FormatBlockCommand final : public ApplyBlockElementCommand {
 public:
     static PassRefPtrWillBeRawPtr<FormatBlockCommand> create(Document& document, const QualifiedName& tagName)
     {
         return adoptRefWillBeNoop(new FormatBlockCommand(document, tagName));
     }
 
     bool preservesTypingStyle() const override { return true; }
 
     static Element* elementForFormatBlockCommand(Range*);
     bool didApply() const { return m_didApply; }
 
 private:
     FormatBlockCommand(Document&, const QualifiedName& tagName);
 
     void formatSelection(const VisiblePosition& startOfSelection, const VisiblePosition& endOfSelection) override;
     void formatRange(const Position& start, const Position& end, const Position& endOfSelection, RefPtrWillBeRawPtr<HTMLElement>&) override;
     EditAction editingAction() const override { return EditActionFormatBlock; }
 
     bool m_didApply;
 };
 
 } // namespace blink
 
 #endif // FormatBlockCommand_h