Revert of GN fixes for the Windows build.

ash/ash.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'chromium_code': 1,
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
     # These files lists are shared with the GN build.
     'ash_sources': [
@@ skipping 898 matching lines @@
       'defines': [
         'ASH_IMPLEMENTATION',
       ],
       'sources': [
         '<@(ash_sources)',
       ],
       'conditions': [
         ['OS=="win"', {
           'sources!': [
             # Note: sources list duplicated in GN build.
+            "host/window_tree_host_factory.cc",
             "sticky_keys/sticky_keys_controller.cc",
             "sticky_keys/sticky_keys_controller.h",
           ],
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         }],
         ['use_x11!=1', {
           'sources!': [
             # Note: sources list duplicated in GN build.
             'accelerators/key_hold_detector.cc',
@@ skipping 314 matching lines @@
       'conditions': [
         ['chromeos==1', {
           'dependencies': [
             '../ui/display/display.gyp:display',
           ],
         }],
       ],
     },
   ],
 }