Prevent base::CheckedNumeric from leaking outside of pdfium.

core/src/fdrm/crypto/fx_crypt.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/fxcrt/fx_basic.h"
 #include "../../../include/fdrm/fx_crypt.h"
+#include "../../../src/fxcrt/fx_safe_types.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 struct rc4_state {
     int x, y, m[256];
 };
 void CRYPT_ArcFourSetup(void* context,  FX_LPCBYTE key,  FX_DWORD length )
 {
     rc4_state *s = (rc4_state*)context;
     int i, j, k, *m, a;
@@ skipping 231 matching lines @@
     CRYPT_MD5Finish(&ctx, digest);
 }
 static FX_BOOL (*g_PubKeyDecryptor)(FX_LPCBYTE pData, FX_DWORD size, FX_LPBYTE data_buf, FX_DWORD& data_len) = NULL;
 void CRYPT_SetPubKeyDecryptor(FX_BOOL (*func)(FX_LPCBYTE pData, FX_DWORD size, FX_LPBYTE data_buf, FX_DWORD& data_len))
 {
     g_PubKeyDecryptor = func;
 }
 #ifdef __cplusplus
 };
 #endif