Add test infrastructure for the file-picker modal test

chrome/browser/ui/libgtk2ui/libgtk2ui.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,
   },
   'targets': [
     {
@@ skipping 64 matching lines @@
         'menu_util.h',
         'native_theme_gtk2.cc',
         'native_theme_gtk2.h',
         'print_dialog_gtk2.cc',
         'print_dialog_gtk2.h',
         'printing_gtk2_util.cc',
         'printing_gtk2_util.h',
         'select_file_dialog_impl.cc',
         'select_file_dialog_impl.h',
         'select_file_dialog_impl_gtk2.cc',
+        'select_file_dialog_impl_gtk2.h',
         'select_file_dialog_impl_kde.cc',
         'skia_utils_gtk2.cc',
         'skia_utils_gtk2.h',
         'unity_service.cc',
         'unity_service.h',
         'x11_input_method_context_impl_gtk2.cc',
         'x11_input_method_context_impl_gtk2.h',
       ],
       'conditions': [
         ['use_gconf==0', {
@@ skipping 20 matching lines @@
             '-Wno-unused-function',
 
             # G_STATIC_ASSERT uses a typedef as a static_assert.
             '-Wno-unused-local-typedef',
           ],
         }],
       ],
     },
   ],
 }