Launch nexes from mojo_shell.

mojo/public/platform/nacl/mojo_main_thunk.cc

Index: mojo/public/platform/nacl/mojo_main_thunk.cc
diff --git a/mojo/public/platform/nacl/mojo_main_thunk.cc b/mojo/public/platform/nacl/mojo_main_thunk.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7cb5b52d993b47a4add507b53cfaa8022950f66f
--- /dev/null
+++ b/mojo/public/platform/nacl/mojo_main_thunk.cc
@@ -0,0 +1,12 @@
+// Copyright 2015 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.
+
+#include "mojo/public/c/system/main.h"
+#include "mojo/public/platform/nacl/mojo_initial_handle.h"
+
+int main() {
+  MojoHandle handle;
+  _MojoGetInitialHandle(&handle);
+  return MojoMain(handle);
+}