Remove wm_flow, browser, nesting_app examples

examples/browser/BUILD.gn

-# 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("//build/config/ui.gni")
-import("//mojo/public/mojo_application.gni")
-import("//mojo/public/tools/bindings/mojom.gni")
-
-mojo_native_application("browser") {
-  sources = [
-    "browser.cc",
-  ]
-
-  deps = [
-    ":bindings",
-    "//base",
-    "//examples/window_manager:bindings",
-    "//mojo/application",
-    "//mojo/converters/geometry",
-    "//mojo/services/geometry/interfaces",
-    "//mojo/services/navigation/interfaces",
-    "//mojo/services/view_manager/cpp",
-    "//mojo/services/view_manager/interfaces",
-    "//third_party/icu",
-    "//url",
-  ]
-}
-
-mojom("bindings") {
-  sources = [
-    "browser_host.mojom",
-  ]
-}