Make the NaCl windows 64 bit binaries not depend on chrome targets.

content/content_app.gypi

 # Copyright (c) 2011 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.
 
 {
   'targets': [
     {
       'target_name': 'content_app',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         'content_browser',
         'content_common',
         '../base/base.gyp:base',
         '../base/base.gyp:base_i18n',
         '../crypto/crypto.gyp:crypto',
         '../ui/ui.gyp:ui',
       ],
       'sources': [
         'app/content_main.cc',
         'app/content_main.h',
         'app/content_main_delegate.h',
         'app/sandbox_helper_win.cc',
         'app/sandbox_helper_win.h',
+        'app/startup_helper_win.cc',
+        'app/startup_helper_win.h',
       ],
       'conditions': [
         ['OS=="win"', {
           'dependencies': [
             '../sandbox/sandbox.gyp:sandbox',
           ],
         }],
       ],
     },
   ],
 }