Refators display related functionality into own class

components/mus/ws/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("//testing/test.gni")
 import("//mojo/public/mojo_application.gni")
 import("//mojo/public/mojo_application_manifest.gni")
 
 source_set("lib") {
   sources = [
     "access_policy.h",
     "access_policy_delegate.h",
     "connection_manager.cc",
     "connection_manager.h",
     "connection_manager_delegate.cc",
     "connection_manager_delegate.h",
     "default_access_policy.cc",
     "default_access_policy.h",
     "display.cc",
     "display.h",
     "display_binding.cc",
     "display_binding.h",
+    "display_manager.cc",
+    "display_manager.h",
+    "display_manager_delegate.h",
     "event_dispatcher.cc",
     "event_dispatcher.h",
     "event_dispatcher_delegate.h",
     "focus_controller.cc",
     "focus_controller.h",
     "focus_controller_delegate.h",
     "focus_controller_observer.h",
     "operation.cc",
     "operation.h",
     "platform_display.cc",
@@ skipping 185 matching lines @@
 
   if (use_x11) {
     deps += [ "//tools/xdisplaycheck" ]
   }
 }
 
 mojo_application_manifest("manifest") {
   application_name = "mus_apptests"
   source = "apptest_manifest.json"
 }