Handle-passing: Allow a handle-passing function to be supplied by Chromium

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 2d76e2662aa353d72038560faa817cc855406fcb..09871ac2e2b9501d4d56867cf49f74b7e42e0d2d 100644
--- a/src/trusted/service_runtime/sel_main_chrome.h
+++ b/src/trusted/service_runtime/sel_main_chrome.h
@@ -41,6 +41,14 @@ struct NaClChromeMainArgs {
    */
   NaClCreateMemoryObjectFunc create_memory_object_func;
 
+#if NACL_WINDOWS
+  /*
+   * Callback to use instead of DuplicateHandle() for copying a
+   * Windows handle to another process.  Optional; may be NULL.
+   */
+  NaClBrokerDuplicateHandleFunc broker_duplicate_handle_func;
+#endif
+
   /* Cache for NaCl validation judgements.  Optional; may be NULL. */
   struct NaClValidationCache *validation_cache;
 };