PDF: Consistently pass FPDF handles by value.

pdf/pdfium/fuzzers/pdfium_fuzzer_helper.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This fuzzer is simplified & cleaned up pdfium/samples/pdfium_test.cc
 
 #include "third_party/pdfium/public/fpdf_ext.h"
 #include "third_party/pdfium/public/fpdf_formfill.h"
 #include "third_party/pdfium/public/fpdfview.h"
 #include "v8/include/v8.h"
 
 class PDFiumFuzzerHelper {
  public:
   virtual ~PDFiumFuzzerHelper();
 
   void RenderPdf(const char* pBuf, size_t len);
 
   virtual int GetFormCallbackVersion() const = 0;
   virtual bool OnFormFillEnvLoaded(FPDF_DOCUMENT doc);
 
  protected:
   PDFiumFuzzerHelper();
 
  private:
-  bool RenderPage(const FPDF_DOCUMENT& doc,
-                  const FPDF_FORMHANDLE& form,
+  bool RenderPage(FPDF_DOCUMENT doc,
+                  FPDF_FORMHANDLE form,
                   const int page_index);
 };