Add a load_status callback hook that is invoked at the end of chrome LoadApp.

src/public/chrome_main.h

 /*
  * 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.
  */
 
 #ifndef NATIVE_CLIENT_SRC_PUBLIC_CHROME_MAIN_H_
 #define NATIVE_CLIENT_SRC_PUBLIC_CHROME_MAIN_H_ 1
 
 #include "native_client/src/include/build_config.h"
@@ skipping 144 matching lines @@
   /*
    * Callback to use for requesting that a debug exception handler be
    * attached to this process for handling hardware exceptions via the
    * Windows debug API.  The data in info/info_size must be passed to
    * NaClDebugExceptionHandlerRun().  Optional; may be NULL.
    */
   int (*attach_debug_exception_handler_func)(const void *info,
                                              size_t info_size);
 #endif
 
+  /*
+   * Callback to run when the initial module load status from a call to
+   * NaClChromeMainStart is known. The callback is run on the same thread
+   * that called NaClChromeMainStart. load_status is zero on success, or a
+   * non-zero error code (from the NaClErrorCode enumeration) on failure.
+   * Optional; may be NULL.
+   */
+  void (*load_status_handler_func)(int load_status);
+
 #if NACL_LINUX || NACL_OSX
   /*
    * The result of sysconf(_SC_NPROCESSORS_ONLN).  The Chrome
    * outer-sandbox prevents the glibc implementation of sysconf from
    * working -- which just reads /proc/cpuinfo or similar file -- so
    * instead, the launcher should fill this in.  In principle this is
    * optional and may be -1, but this will make
    * sysconf(_SC_NPROCESSORS_ONLN) fail and result in some NaCl
    * modules failing.
    *
@@ skipping 78 matching lines @@
  * exit status.
  *
  * This is safer than exit(), which does some teardown that can cause running
  * threads to crash.
  */
 void NaClExit(int code);
 
 EXTERN_C_END
 
 #endif