Add nacl_loader_manifest to catalog_mus.

chrome/app/mash/BUILD.gn

Index: chrome/app/mash/BUILD.gn
diff --git a/chrome/app/mash/BUILD.gn b/chrome/app/mash/BUILD.gn
index ea70a425dffd03c544348be4cb3db02a060bf04c..8c7afa6ac748ef63b25de23ba4962788134b8c5c 100644
--- a/chrome/app/mash/BUILD.gn
+++ b/chrome/app/mash/BUILD.gn
@@ -105,6 +105,10 @@ if (is_chromeos) {
       # TODO(sky): verify if we need this.
       "//services/ui/ime/test_ime_driver:manifest",
     ]
+
+    if (enable_nacl) {
+      embedded_services += [ "//components/nacl/loader:nacl_loader_manifest" ]
+    }
   }
 
   catalog_cpp_source("chrome_mus_catalog") {