Add PPAPI decryptor implementation.

ppapi/ppapi_shared.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': {
     'conditions': [
       ['inside_chromium_build==0', {
         'webkit_src_dir': '../../../..',
       },{
@@ skipping 123 matching lines @@
           'thunk/ppb_broker_api.h',
           'thunk/ppb_broker_thunk.cc',
           'thunk/ppb_browser_font_trusted_api.h',
           'thunk/ppb_browser_font_trusted_thunk.cc',
           'thunk/ppb_buffer_api.h',
           'thunk/ppb_buffer_thunk.cc',
           'thunk/ppb_buffer_trusted_api.h',
           'thunk/ppb_buffer_trusted_thunk.cc',
           'thunk/ppb_char_set_thunk.cc',
           'thunk/ppb_console_thunk.cc',
+          'thunk/ppb_content_decryptor_private_thunk.cc',
           'thunk/ppb_cursor_control_thunk.cc',
           'thunk/ppb_device_ref_api.h',
           'thunk/ppb_device_ref_thunk.cc',
           'thunk/ppb_directory_reader_api.h',
           'thunk/ppb_directory_reader_thunk.cc',
           'thunk/ppb_file_chooser_api.h',
           'thunk/ppb_file_chooser_thunk.cc',
           'thunk/ppb_file_io_api.h',
           'thunk/ppb_file_io_thunk.cc',
           'thunk/ppb_file_io_trusted_thunk.cc',
@@ skipping 141 matching lines @@
               'thunk/ppb_video_layer_thunk.cc',
               'thunk/ppb_websocket_thunk.cc',
               'thunk/ppb_x509_certificate_private_thunk.cc',
             ],
           }],
         ],
       }],
     ],
   },
 }