Undo the startup_helper_win.h change in r143501 because that breaks the sandbox in component builds.

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',
   },
 
@@ skipping 508 matching lines @@
         'shell/shell_main_parts_mac.mm',
         'shell/toplevel_window.cc',
         'shell/toplevel_window.h',
         'shell/widgets.cc',
         'shell/window_type_launcher.cc',
         'shell/window_type_launcher.h',
         'shell/window_watcher.cc',
         'shell/window_watcher.h',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources_standard/ui_resources_standard.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources/ui_resources.rc',
+        '../content/app/startup_helper_win.cc',
         '../ui/views/test/test_views_delegate.cc',
       ],
       'conditions': [
         ['OS=="win"', {
           'msvs_settings': {
             'VCLinkerTool': {
               'SubSystem': '2',  # Set /SUBSYSTEM:WINDOWS
             },
           },
           'dependencies': [
@@ skipping 18 matching lines @@
             'shell/cocoa/app-Info.plist',
           ],
           'xcode_settings': {
             'INFOPLIST_FILE': 'shell/cocoa/app-Info.plist',
           },
         }],
       ],
     },
   ],
 }