Implement the filesystem proxy. This allows the FileRef tests to pass in the...

ppapi/ppapi_shared_proxy.gypi

 # Copyright (c) 2010 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': 'ppapi_shared_impl',
       'type': 'static_library',
       'dependencies': [
@@ skipping 71 matching lines @@
         'proxy/ppb_context_3d_proxy.cc',
         'proxy/ppb_context_3d_proxy.h',
         'proxy/ppb_core_proxy.cc',
         'proxy/ppb_core_proxy.h',
         'proxy/ppb_cursor_control_proxy.cc',
         'proxy/ppb_cursor_control_proxy.h',
         'proxy/ppb_file_chooser_proxy.cc',
         'proxy/ppb_file_chooser_proxy.h',
         'proxy/ppb_file_ref_proxy.cc',
         'proxy/ppb_file_ref_proxy.h',
+        'proxy/ppb_file_system_proxy.cc',
+        'proxy/ppb_file_system_proxy.h',
         'proxy/ppb_flash_proxy.cc',
         'proxy/ppb_flash_proxy.h',
         'proxy/ppb_flash_menu_proxy.cc',
         'proxy/ppb_flash_menu_proxy.h',
         'proxy/ppb_font_proxy.cc',
         'proxy/ppb_font_proxy.h',
         'proxy/ppb_fullscreen_proxy.cc',
         'proxy/ppb_fullscreen_proxy.h',
         'proxy/ppb_gles_chromium_texture_mapping_proxy.cc',
         'proxy/ppb_gles_chromium_texture_mapping_proxy.h',
@@ skipping 37 matching lines @@
         ['OS=="win"', {
         }],
         ['OS=="linux"', {
         }],
         ['OS=="mac"', {
         }]
       ],
     },
   ],
 }