Add mus_demo mojo app.

components/mus/demo/BUILD.gn

Index: components/mus/demo/BUILD.gn
diff --git a/mash/init/BUILD.gn b/components/mus/demo/BUILD.gn
similarity index 61%
copy from mash/init/BUILD.gn
copy to components/mus/demo/BUILD.gn
index 900a31e13060f120d0914200d81e0ba1d9fcee57..fd9cb185e7a5206247eee06ac0a0c89836dcc790 100644
--- a/mash/init/BUILD.gn
+++ b/components/mus/demo/BUILD.gn
@@ -2,37 +2,41 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/ui.gni")
 import("//mojo/public/mojo_application.gni")
 import("//mojo/public/mojo_application_manifest.gni")
-import("//mojo/public/tools/bindings/mojom.gni")
-import("//tools/grit/repack.gni")
 
-mojo_native_application("init") {
-  output_name = "mash_init"
+mojo_native_application("mus_demo") {
   sources = [
-    "init.cc",
-    "init.h",
     "main.cc",
+    "mus_demo.cc",
+    "mus_demo.h",
   ]
 
   deps = [
     "//base",
+    "//components/bitmap_uploader",
     "//components/mus/public/cpp",
     "//components/mus/public/interfaces",
-    "//mash/init/public/interfaces",
-    "//mash/login/public/interfaces",
     "//mojo/public/cpp/bindings",
-    "//mojo/services/tracing/public/cpp",
     "//mojo/shell/public/cpp",
+    "//mojo/shell/public/cpp:sources",
+    "//skia",
+    "//ui/gfx/geometry",
   ]
 
   data_deps = [
     ":manifest",
+    "//components/mus",
   ]
 }
 
 mojo_application_manifest("manifest") {
-  application_name = "mash_init"
+  application_name = "mus_demo"
   source = "manifest.json"
 }
+
+group("demo") {
+  deps = [
+    ":mus_demo",
+  ]
+}