Make a NaClDesc ctor for creating descs from NaClFileInfo.

src/trusted/desc_cacheability/desc_cacheability.c

 /*
  * Copyright (c) 2013 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "native_client/src/trusted/desc_cacheability/desc_cacheability.h"
 
 #include "native_client/src/include/portability.h"
 #include "native_client/src/public/desc_metadata_types.h"
+#include "native_client/src/public/nacl_file_info.h"
 #include "native_client/src/shared/platform/nacl_log.h"
 #include "native_client/src/trusted/desc/nacl_desc_base.h"
 #include "native_client/src/trusted/desc/nacl_desc_io.h"
 #include "native_client/src/trusted/service_runtime/include/sys/fcntl.h"
-#include "native_client/src/trusted/validator/nacl_file_info.h"
 #include "native_client/src/trusted/validator/rich_file_info.h"
 #include "native_client/src/trusted/validator/validation_cache.h"
 
 int NaClDescSetFileToken(struct NaClDesc *desc,
                          struct NaClFileToken const *token) {
   int error;
   error = (*NACL_VTBL(NaClDesc, desc)->
            SetMetadata)(desc,
                         NACL_DESC_METADATA_FILE_TOKEN_TYPE,
                         sizeof *token, (uint8_t const *) token);
@@ skipping 84 matching lines @@
             " file token\n");
   } else {
     replacement = NaClExchangeFileTokenForMappableDesc(&file_token,
                                                        validation_cache);
     if (NULL != replacement) {
       NaClDescUnref(desc);
       *desc_in_out = replacement;
     }
   }
 }