Update the UI examples.

examples/png_viewer/BUILD.gn

Index: examples/png_viewer/BUILD.gn
diff --git a/examples/png_viewer/BUILD.gn b/examples/png_viewer/BUILD.gn
deleted file mode 100644
index 16061bc0fbb64379cf576c93b78e22139e14deb0..0000000000000000000000000000000000000000
--- a/examples/png_viewer/BUILD.gn
+++ /dev/null
@@ -1,24 +0,0 @@
-# Copyright 2014 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("//mojo/public/mojo_application.gni")
-
-mojo_native_application("png_viewer") {
-  sources = [
-    "png_viewer.cc",
-  ]
-
-  deps = [
-    "//examples/bitmap_uploader",
-    "//mojo/application",
-    "//mojo/application:content_handler",
-    "//mojo/data_pipe_utils",
-    "//mojo/public/cpp/bindings",
-    "//mojo/public/cpp/utility",
-    "//mojo/services/content_handler/interfaces",
-    "//mojo/services/network/interfaces",
-    "//mojo/services/view_manager/cpp",
-    "//ui/gfx",
-  ]
-}