Enable mmap and identity-based validation caching on pnacl-{llc,ld}.nexe

ppapi/api/private/ppb_nacl_private.idl

Index: ppapi/api/private/ppb_nacl_private.idl
diff --git a/ppapi/api/private/ppb_nacl_private.idl b/ppapi/api/private/ppb_nacl_private.idl
index e10b7b7e5bcccb7ae5ae09a1c46dbc1cb799b0b4..66fa34582742daaeae2513c98f65db4695feafd6 100644
--- a/ppapi/api/private/ppb_nacl_private.idl
+++ b/ppapi/api/private/ppb_nacl_private.idl
@@ -203,8 +203,12 @@ interface PPB_NaCl_Private {
 
   /* Returns a read-only file descriptor of a file rooted in the Pnacl
    * component directory, or an invalid handle on failure.
+   * The metadata |file_token_*| are 0 on failure.
    */
-  PP_FileHandle GetReadonlyPnaclFd([in] str_t filename);
+  PP_FileHandle GetReadonlyPnaclFd([in] str_t filename,
+                                   [in] PP_Bool is_executable,
+                                   [out] uint64_t file_token_lo,
+                                   [out] uint64_t file_token_hi);
 
   /* This creates a temporary file that will be deleted by the time
    * the last handle is closed (or earlier on POSIX systems), and
@@ -254,7 +258,7 @@ interface PPB_NaCl_Private {
 
   /* Opens a NaCl executable file in the application's extension directory
    * corresponding to the file URL and returns a file descriptor, or an invalid
-   * handle on failure. |metadata| is left unchanged on failure.
+   * handle on failure. The metadata |file_token*| are 0 on failure.
    */
   PP_FileHandle OpenNaClExecutable([in] PP_Instance instance,
                                    [in] str_t file_url,