Remove remote tree host and some related input and metro_driver code

ui/shell_dialogs/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")
 if (is_android) {
   import("//build/config/android/config.gni")
 }
 
@@ skipping 52 matching lines @@
     include_dirs = [ "$root_gen_dir/ui" ]
     libs = [ "jnigraphics" ]
   }
 
   if (is_android && use_aura) {
     sources += [
       "select_file_dialog_auraandroid.cc",
       "select_file_dialog_auraandroid.h",
     ]
   }
-
-  if (is_win) {
-    deps += [ "//win8:metro_viewer" ]
-  }
 }
 
 test("shell_dialogs_unittests") {
   sources = [
     "select_file_dialog_win_unittest.cc",
   ]
 
   deps = [
     ":shell_dialogs",
     "//base",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
     "//testing/gtest",
   ]
 }