Partly change IRT load-skipping to be explicit.

src/trusted/service_runtime/sel_main_chrome.h

Index: src/trusted/service_runtime/sel_main_chrome.h
diff --git a/src/trusted/service_runtime/sel_main_chrome.h b/src/trusted/service_runtime/sel_main_chrome.h
index 5c858dc8b1d1d71abe67e0271cca278b5aa52150..48ab0130d563964b1aeb54abc84ba51e553e1401 100644
--- a/src/trusted/service_runtime/sel_main_chrome.h
+++ b/src/trusted/service_runtime/sel_main_chrome.h
@@ -34,7 +34,8 @@ struct NaClChromeMainArgs {
   /*
    * File descriptor for the NaCl integrated runtime (IRT) library.
    * Note that this is a file descriptor even on Windows (where file
-   * descriptors are emulated by the C runtime library).  Required.
+   * descriptors are emulated by the C runtime library).  Optional; may be -1.

[Mark Seaborn, 2013/01/03 23:36:40]

Nit: can you word-wrap to roughly the same length as the rest of the paragraph?

[jvoung (off chromium), 2013/01/04 00:05:31]

Done.

+   * This is only optional for non-ABI stable nexes.

[Mark Seaborn, 2013/01/03 23:36:40]

"optional when loading nexes that don't follow NaCl's stable ABI, such as the
PNaCl translator" - just to be more explicit?

[jvoung (off chromium), 2013/01/04 00:05:31]

Done.

    */
   int irt_fd;