Fix page leaks in an embedder test

public/fpdf_formfill.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 PUBLIC_FPDF_FORMFILL_H_
 #define PUBLIC_FPDF_FORMFILL_H_
 
 #include "fpdfview.h"
@@ skipping 557 matching lines @@
   *       document    -   Handle to document. Returned by FPDF_LoadDocument
   * function.
   *       nPageIndex  -   Index number of the page. 0 for the first page.
   * Return value:
   *       Handle to the page. Returned by FPDF_LoadPage function.
   * Comments:
   *       In some cases, the document-level JavaScript action may refer to a
   * page which hadn't been loaded yet.
   *       To successfully run the javascript action, implementation need to load
   * the page for SDK.
+  *       If getting a CPDFXFA_Page from this function, needs to call release()
+  * on that page when finished.
   * */
   FPDF_PAGE (*FFI_GetPage)(struct _FPDF_FORMFILLINFO* pThis,
                              FPDF_DOCUMENT document,
                              int nPageIndex);
 
   /**
   * Method: FFI_GetCurrentPage
   *       This method receives the current page pointer.
   * Interface Version:
   *           1
@@ skipping 1163 matching lines @@
 FPDF_StringHandleAddString(FPDF_STRINGHANDLE stringHandle,
                            FPDF_BYTESTRING bsText,
                            FPDF_DWORD size);
 #endif  // PDF_ENABLE_XFA
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // PUBLIC_FPDF_FORMFILL_H_