Make a NaClDesc ctor for creating descs from NaClFileInfo.

src/trusted/desc_cacheability/desc_cacheability.h

 /*
  * 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.
  */
 
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_DESC_CACHEABILITY_DESC_CACHEABILITY_H_
 #define NATIVE_CLIENT_SRC_TRUSTED_DESC_CACHEABILITY_DESC_CACHEABILITY_H_
 
 #include "native_client/src/include/nacl_base.h"
 
 EXTERN_C_BEGIN
 
 struct NaClDesc;
 struct NaClFileToken;
 struct NaClValidationCache;
 
 /*
- * NaClDescSetFileToken associates the contents of |token| with |desc|
- * as NaClDesc metadata.  Any other metadata previously associated
- * with |desc| is released / destroyed.  Returns non-zero value for
- * success.  (Boolean function.)
- */
-int NaClDescSetFileToken(struct NaClDesc *desc,
-                         struct NaClFileToken const *token);
-
-/*
- * NaClDescGetFileToken checks if there is metadata associated with
- * |desc| that contains a previously serialized NaClFileToken object.
- * If so, it writes the NaClFileToken pointed to by |out_token| with
- * the file token, and returns a non-zero value.  (Boolean function.)
- */
-int NaClDescGetFileToken(struct NaClDesc *desc,
-                         struct NaClFileToken *out_token);
-
-/*
  * NaClExchangeFileTokenForMappableDesc checks the |file_token| with
  * the |validation_cache| and, if the file token is valid, i.e., for a
  * file that should be safe to map (immutable for the duration of our
  * execution), returns a NaClDesc for that file that should be used
  * for the memory mapping.
  */
 struct NaClDesc *NaClExchangeFileTokenForMappableDesc(
     struct NaClFileToken *file_token,
     struct NaClValidationCache *validation_cache);
 
 /*
  * NaClReplaceDescIfValidationCacheAssertsMappable checks
  * |*desc_in_out| to see if it contains a NaClFileToken as metadata,
  * and if so, queries the |validation_cache| with it. If the
  * validation cache says that this is a "safe" file by returning what
  * should be an equivalent file descriptor (in the Chrome embedding,
  * via a separate, trusted communication link) the |*desc_in_out|
  * reference count is decremented and then the NaClDesc pointer is
  * replaced with one that wraps the validator-supplied file
  * descriptor.
  */
 void NaClReplaceDescIfValidationCacheAssertsMappable(
     struct NaClDesc **desc_in_out,
     struct NaClValidationCache *validation_cache);
 
 EXTERN_C_END
 
 #endif