HostResolver is exposed to Native Client.

ppapi/native_client/src/shared/ppapi_proxy/nacl.scons

 # -*- python -*-
 # 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.
 
 Import('env')
 
 # Underlay $SOURCE_ROOT/gpu in this directory.
 Dir('.').addRepository(Dir('#/../gpu'))
 
@@ skipping 50 matching lines @@
     'plugin_ppb_cursor_control.cc',
     'plugin_ppb_file_io.cc',
     'plugin_ppb_file_system.cc',
     'plugin_ppb_file_ref.cc',
     'plugin_ppb_find.cc',
     'plugin_ppb_font.cc',
     'plugin_ppb_fullscreen.cc',
     'plugin_ppb_gamepad.cc',
     'plugin_ppb_graphics_2d.cc',
     'plugin_ppb_graphics_3d.cc',
+    'plugin_ppb_host_resolver_private.cc',
     'plugin_ppb_image_data.cc',
     'plugin_ppb_input_event.cc',
     'plugin_ppb_instance.cc',
     'plugin_ppb_memory.cc',
     'plugin_ppb_messaging.cc',
     'plugin_ppb_mouse_lock.cc',
     'plugin_ppb_net_address_private.cc',
     'plugin_ppb_pdf.cc',
     'plugin_ppb_scrollbar.cc',
     'plugin_ppb_tcp_server_socket_private.cc',
@@ skipping 36 matching lines @@
          'srpc',
          'gio',
          'platform',
         ])
 
 header_install = env.AddHeaderToSdk(['ppruntime.h'])
 env.AddLibraryToSdk(libppruntime)
 
 # Clients that overload main() will use ppruntime.h.
 env.Requires(libppruntime, header_install)