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

content/content_tests.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'test_support_content',
       'type': 'static_library',
       'defines!': ['CONTENT_IMPLEMENTATION'],
@@ skipping 202 matching lines @@
         '../webkit/support/webkit_support.gyp:dom_storage',
         '../webkit/support/webkit_support.gyp:fileapi',
         '../webkit/support/webkit_support.gyp:glue',
         '../webkit/support/webkit_support.gyp:quota',
         '../webkit/support/webkit_support.gyp:webkit_media',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
+        'app/startup_helper_win.cc',
         'browser/accessibility/browser_accessibility_mac_unittest.mm',
         'browser/accessibility/browser_accessibility_manager_unittest.cc',
         'browser/accessibility/browser_accessibility_win_unittest.cc',
         'browser/appcache/chrome_appcache_service_unittest.cc',
         'browser/browser_thread_unittest.cc',
         'browser/browser_url_handler_impl_unittest.cc',
         'browser/child_process_security_policy_unittest.cc',
         'browser/debugger/devtools_manager_unittest.cc',
         'browser/device_orientation/provider_unittest.cc',
         'browser/download/base_file_unittest.cc',
@@ skipping 282 matching lines @@
         '../ui/ui.gyp:ui',
         '../webkit/support/webkit_support.gyp:glue',
       ],
       'include_dirs': [
         '..',
       ],
       'defines': [
         'HAS_OUT_OF_PROC_TEST_RUNNER',
       ],
       'sources': [
+        'app/startup_helper_win.cc',
         'public/test/test_launcher.h',
         'test/content_browser_test.h',
         'test/content_browser_test.cc',
         'test/content_test_launcher.cc',
       ],
       'conditions': [
         ['OS=="win"', {
           'resource_include_dirs': [
             '<(SHARED_INTERMEDIATE_DIR)/webkit',
           ],
@@ skipping 131 matching lines @@
               '<(PRODUCT_DIR)/lib.java/chromium_base.jar',
               '<(PRODUCT_DIR)/lib.java/chromium_content.jar',
             ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }