Add NetworkListObserver utility class.

ppapi/ppapi_sources.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.
 
 {
   'variables': {
     'c_source_files': [
       'c/pp_array_output.h',
       'c/pp_bool.h',
       'c/pp_completion_callback.h',
@@ skipping 270 matching lines @@
       'cpp/trusted/file_io_trusted.cc',
       'cpp/trusted/file_io_trusted.h',
 
       # Utility sources.
       'utility/completion_callback_factory.h',
       'utility/non_thread_safe_ref_count.h',
       'utility/graphics/paint_aggregator.cc',
       'utility/graphics/paint_aggregator.h',
       'utility/graphics/paint_manager.cc',
       'utility/graphics/paint_manager.h',
+      'utility/private/network_list_observer_private.cc',
+      'utility/private/network_list_observer_private.h',
       'utility/threading/simple_thread.cc',
       'utility/threading/simple_thread.h',
       'utility/websocket/websocket_api.cc',
       'utility/websocket/websocket_api.h',
     ],
     #
     # Common Testing source for trusted and untrusted (NaCl) pugins.
     #
     'test_common_source_files': [
       # Common test files
@@ skipping 152 matching lines @@
           'c/dev/ppb_transport_dev.h',
         ],
         'cpp_source_files': [
           'cpp/dev/transport_dev.cc',
           'cpp/dev/transport_dev.h',
         ],
       },
     }],
   ],
 }