Add PPAPI decryptor interfaces.

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 60 matching lines @@
       'c/dev/ppb_memory_dev.h',
       'c/dev/ppb_message_loop_dev.h',
       'c/dev/ppb_resource_array_dev.h',
       'c/dev/ppb_scrollbar_dev.h',
       'c/dev/ppb_testing_dev.h',
       'c/dev/ppb_text_input_dev.h',
       'c/dev/ppb_url_util_dev.h',
       'c/dev/ppb_video_decoder_dev.h',
       'c/dev/ppb_widget_dev.h',
       'c/dev/ppb_zoom_dev.h',
+      'c/dev/ppp_content_decryption_module_dev.h',
       'c/dev/ppp_cursor_control_dev.h',
       'c/dev/ppp_find_dev.h',
       'c/dev/ppp_network_state_dev.h',
       'c/dev/ppp_scrollbar_dev.h',
       'c/dev/ppp_selection_dev.h',
       'c/dev/ppp_text_input_dev.h',
       'c/dev/ppp_video_decoder_dev.h',
       'c/dev/ppp_widget_dev.h',
       'c/dev/ppp_zoom_dev.h',
 
@@ skipping 346 matching lines @@
       'tests/test_x509_certificate_private.h',
 
       # Deprecated test cases.
       'tests/test_instance_deprecated.cc',
       'tests/test_instance_deprecated.h',
       'tests/test_var_deprecated.cc',
       'tests/test_var_deprecated.h',
     ],
   },
 }