Add a NaCl-Private interface for opening files in DIR_PNACL_COMPONENT.

ppapi/api/private/finish_writing_these/ppb_nacl_private.idl

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* This file contains NaCl private interfaces. */
 
 /* PPB_NaCl_Private */
-interface PPB_NaCl_Private_0_5 {
+interface PPB_NaCl_Private_0_6 {
   /* This function launches NaCl's sel_ldr process.  On success, the function
    * returns true, otherwise it returns false.  When it returns true, it will
    * write |socket_count| nacl::Handles to imc_handles.
    */
   bool LaunchSelLdr([in] PP_Instance instance,
                     [in] str_t alleged_url,
                     [in] int32_t socket_count,
                     [out] mem_t imc_handles);
 
   /* This function starts the PPAPI proxy so the nexe can communicate with the
    * browser's renderer process.
    */
   bool StartPpapiProxy([in] PP_Instance instance);
 
   /* On POSIX systems, this function returns the file descriptor of
    * /dev/urandom.  On non-POSIX systems, this function returns 0.
    */
   int32_t UrandomFD();
 
   /* Whether the Pepper 3D interfaces should be disabled in the NaCl PPAPI
    * proxy. This is so paranoid admins can effectively prevent untrusted shader
    * code to be processed by the graphics stack.
    */
   bool Are3DInterfacesDisabled();
+
+  /* Returns a read-only file descriptor of a file rooted in the Pnacl
+   * component directory, or -1 on error.
+   * Do we want this to take a completion callback and be async, or
+   * could we make this happen on another thread?
+   */
+  int32_t GetReadonlyPnaclFd([in] str_t filename);
 };