Remove DisplayChangeObserver ash dependencies.

ui/display/manager/BUILD.gn

 # 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")
 
 component("manager") {
   sources = [
     "chromeos/apply_content_protection_task.cc",
     "chromeos/apply_content_protection_task.h",
@@ skipping 25 matching lines @@
 
   public_deps = [
     "//ui/display",
   ]
 
   deps = [
     "//base",
     "//ui/base",
     "//ui/display/util",
     "//ui/events/devices",
+    "//ui/strings",
   ]
 
   defines = [ "DISPLAY_MANAGER_IMPLEMENTATION" ]
 
   if (use_x11) {
     deps += [ "//ui/gfx/x" ]
   }
 
   if (is_chromeos && use_x11) {
     sources += [
@@ skipping 12 matching lines @@
     configs += [
       "//build/config/linux:x11",
       "//build/config/linux:xext",
       "//build/config/linux:xi",
       "//build/config/linux:xrandr",
     ]
 
     deps += [ "//ui/events/platform" ]
   }
 }