Add IRT interface for PNaCl's sandboxed linker to use to talk to Chromium

src/untrusted/irt/irt_interfaces.c

 /*
  * Copyright (c) 2012 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 <string.h>
 
 #include "native_client/src/include/nacl_compiler_annotations.h"
 #include "native_client/src/include/nacl_macros.h"
@@ skipping 106 matching lines @@
    */
   { NACL_IRT_EXCEPTION_HANDLING_v0_1, &nacl_irt_exception_handling,
     sizeof(nacl_irt_exception_handling), non_pnacl_filter },
   { NACL_IRT_DEV_LIST_MAPPINGS_v0_1, &nacl_irt_dev_list_mappings,
     sizeof(nacl_irt_dev_list_mappings), list_mappings_filter },
   /*
    * "irt-code-data-alloc" is not supported under PNaCl.
    */
   { NACL_IRT_CODE_DATA_ALLOC_v0_1, &nacl_irt_code_data_alloc,
     sizeof(nacl_irt_code_data_alloc), non_pnacl_filter },
+  /*
+   * TODO(mseaborn): Ideally this interface should be hidden in processes
+   * that aren't PNaCl sandboxed translator processes.  However, we haven't
+   * yet plumbed though a flag to indicate when a NaCl process is a PNaCl
+   * translator process.  The risk of an app accidentally depending on the
+   * presence of this interface is much lower than for other non-stable IRT
+   * interfaces, because this interface is not useful to apps.
+   */
+  { NACL_IRT_PRIVATE_PNACL_TRANSLATOR_LINK_v0_1,
+    &nacl_irt_private_pnacl_translator_link,
+    sizeof(nacl_irt_private_pnacl_translator_link), NULL },
 };
 
 size_t nacl_irt_query_core(const char *interface_ident,
                            void *table, size_t tablesize) {
   return nacl_irt_query_list(interface_ident, table, tablesize,
                              irt_interfaces, sizeof(irt_interfaces));
 }