Fix IWYU in formfiller/ directory.

fpdfsdk/include/fsdk_actionhandler.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef _FSDK_ACTIONHANDLER_H_
 #define _FSDK_ACTIONHANDLER_H_
 
+#include "../../core/include/fpdfdoc/fpdf_doc.h"
+#include "../../core/include/fxcrt/fx_string.h"
+#include "fsdk_baseform.h"
 
+class CFX_PtrList;
 class CPDFDoc_Environment;
+class CPDFSDK_Annot;
+class CPDFSDK_Document;
+class CPDF_Bookmark;
+class CPDF_Dictionary;
 class IFXJS_Runtime;
 
 class CPDFSDK_FormActionHandler
 {
 public:
         FX_BOOL DoAction_Hide(const CPDF_Action& action, CPDFSDK_Document* pDocument);
         FX_BOOL DoAction_SubmitForm(const CPDF_Action& action, CPDFSDK_Document* pDocument);
         FX_BOOL DoAction_ResetForm(const CPDF_Action& action, CPDFSDK_Document* pDocument);
         FX_BOOL DoAction_ImportData(const CPDF_Action& action, CPDFSDK_Document* pDocument);
 };
@@ skipping 50 matching lines @@
         void                            DoAction_Named(CPDFSDK_Document* pDocument, const CPDF_Action& action);
         void                            DoAction_SetOCGState(CPDFSDK_Document* pDocument, /*CReader_DocView* pDocView,*/ const CPDF_Action& action);
         
 private:
         CPDFSDK_FormActionHandler*              m_pFormActionHandler;
         CPDFSDK_MediaActionHandler*             m_pMediaActionHandler;
 };
 
 #endif //_BA_ACTIONHANDLER_H_