Add //ui/* to "gn check"

ui/platform_window/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")
 
 source_set("platform_window") {
   sources = [
     "platform_ime_controller.h",
     "platform_window.h",
     "platform_window_delegate.h",
     "text_input_state.cc",
     "text_input_state.h",
   ]
 
   deps = [
     "//base",
     "//ui/base",
+    "//ui/base/ime",
     "//ui/gfx",
   ]
 }
 
 group("platform_impls") {
   public_deps = [
     "//ui/platform_window/stub",
   ]
   if (is_android) {
     public_deps += [
       "//ui/platform_window/android",
       "//ui/platform_window/android:jni_headers",
     ]
   } else if (use_x11) {
     public_deps += [ "//ui/platform_window/x11" ]
   } else if (is_win) {
     public_deps += [ "//ui/platform_window/win" ]
   }
 }