Remove unused ASH files from GN build script

chrome/browser/ui/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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
@@ skipping 271 matching lines @@
       "//ash",
       "//ash:ash_with_content",
       "//ash/strings",
       "//ash/sysui/public/interfaces",
       "//components/user_manager",
       "//mash/shelf/public/interfaces",
       "//ui/app_list/presenter",
       "//ui/app_list/presenter:mojom",
       "//ui/keyboard:mojom",
     ]
-    if (!is_chromeos) {
-      sources += rebase_path(gypi_values.chrome_browser_ui_ash_non_chromeos,
-                             ".",
-                             "//chrome")
-    }
   } else {  # Not ash.
     sources += rebase_path(gypi_values.chrome_browser_ui_non_ash_sources,
                            ".",
                            "//chrome")
   }
   if (toolkit_views) {
     sources += rebase_path(gypi_values.chrome_browser_ui_views_sources,
                            ".",
                            "//chrome")
     deps += [ "//components/constrained_window" ]
@@ skipping 408 matching lines @@
     "//chrome/browser",
     "//content/public/browser",
     "//content/public/common",
     "//content/test:test_support",
     "//net:test_support",
     "//skia",
     "//testing/gtest",
     "//ui/base",
   ]
 }