Make (and verify) public/ files compile under C.

fpdfsdk/src/fpdfview.cpp

 // 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
 
 #include "../include/fsdk_define.h"
 #include "../include/fsdk_mgr.h"
 #include "../include/fsdk_rendercontext.h"
 #include "../../public/fpdfview.h"
@@ skipping 807 matching lines @@
         if (!document)
                 return NULL;
         if (!name || name[0] == 0) 
                 return NULL;
 
         CPDF_Document* pDoc = (CPDF_Document*)document;
         CPDF_NameTree name_tree(pDoc, FX_BSTRC("Dests"));
         return name_tree.LookupNamedDest(pDoc, name);
 }
 
-DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document, int index, void* buffer, long& buflen)
+DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document, int index, void* buffer, long* buflen)
 {
     if (!buffer)
-        buflen = 0;
+        *buflen = 0;
     if (!document || index < 0) return NULL;
     CPDF_Document* pDoc = (CPDF_Document*)document;
 
     CPDF_Dictionary* pRoot = pDoc->GetRoot();
     if (!pRoot) return NULL;
 
     CPDF_Object* pDestObj = NULL;
     CFX_ByteString bsName;
     CPDF_NameTree nameTree(pDoc, FX_BSTRC("Dests"));
     int count = nameTree.GetCount();
@@ skipping 16 matching lines @@
     if (!pDestObj) return NULL;
     if (pDestObj->GetType() == PDFOBJ_DICTIONARY) {
         pDestObj = ((CPDF_Dictionary*)pDestObj)->GetArray(FX_BSTRC("D"));
         if (!pDestObj) return NULL;
     }
     if (pDestObj->GetType() != PDFOBJ_ARRAY) return NULL;
     CFX_WideString wsName = PDF_DecodeText(bsName);
     CFX_ByteString utf16Name = wsName.UTF16LE_Encode();
     unsigned int len = utf16Name.GetLength();
     if (!buffer) {
-        buflen = len;
-    } else if (buflen >= len) {
+        *buflen = len;
+    } else if (*buflen >= len) {
         memcpy(buffer, utf16Name.c_str(), len);
-        buflen = len;
+        *buflen = len;
     } else {
-        buflen = -1;
+        *buflen = -1;
     }
     return (FPDF_DEST)pDestObj;
 }