Removes example code that isn't correctly wired up

mash/screenlock/BUILD.gn

Index: mash/screenlock/BUILD.gn
diff --git a/mash/screenlock/BUILD.gn b/mash/screenlock/BUILD.gn
deleted file mode 100644
index 6078833ceba7738b5adb3eb8bd4cc0f6605870c5..0000000000000000000000000000000000000000
--- a/mash/screenlock/BUILD.gn
+++ /dev/null
@@ -1,44 +0,0 @@
-# Copyright 2016 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.
-
-import("//build/config/ui.gni")
-import("//services/service_manager/public/cpp/service.gni")
-import("//services/service_manager/public/service_manifest.gni")
-import("//mojo/public/tools/bindings/mojom.gni")
-import("//tools/grit/repack.gni")
-
-service("screenlock") {
-  sources = [
-    "main.cc",
-    "screenlock.cc",
-    "screenlock.h",
-  ]
-
-  deps = [
-    "//ash/public/cpp",
-    "//ash/public/interfaces",
-    "//base",
-    "//mash/session/public/interfaces",
-    "//mojo/common",
-    "//mojo/public/cpp/bindings",
-    "//services/service_manager/public/cpp",
-    "//services/service_manager/public/cpp:sources",
-    "//services/tracing/public/cpp",
-    "//services/ui/public/cpp",
-    "//ui/views",
-    "//ui/views/mus:for_mojo_application",
-  ]
-
-  resources = [ "$root_out_dir/views_mus_resources.pak" ]
-
-  data_deps = [
-    ":manifest",
-    "//services/ui",
-  ]
-}
-
-service_manifest("manifest") {
-  name = "screenlock"
-  source = "manifest.json"
-}