Revert "Delete the ViewManager and WindowManager services."

mojo/services/window_manager/interfaces/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/module_args/mojo.gni")
 import("$mojo_sdk_root/mojo/public/tools/bindings/mojom.gni")
 
 mojom("interfaces") {
   sources = [
-    "native_viewport.mojom",
+    "window_manager.mojom",
+    "window_manager_internal.mojom",
   ]
 
   import_dirs = [ get_path_info("../../", "abspath") ]
 
-  public_deps = [
+  mojo_sdk_deps = [ "mojo/public/interfaces/application" ]
+
+  deps = [
     "../../geometry/interfaces",
-    "../../gpu/interfaces",
     "../../input_events/interfaces",
-    "../../surfaces/interfaces:surface_id",
   ]
 }