Add the PPAPI X509 Certificate interface and implementation.

ppapi/ppapi_proxy.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.
 
 {
   'targets': [
     {
       'target_name': 'ppapi_proxy',
       'type': '<(component)',
       'dependencies': [
@@ skipping 113 matching lines @@
         'proxy/ppb_url_loader_proxy.cc',
         'proxy/ppb_url_loader_proxy.h',
         'proxy/ppb_url_response_info_proxy.cc',
         'proxy/ppb_url_response_info_proxy.h',
         'proxy/ppb_var_deprecated_proxy.cc',
         'proxy/ppb_var_deprecated_proxy.h',
         'proxy/ppb_video_capture_proxy.cc',
         'proxy/ppb_video_capture_proxy.h',
         'proxy/ppb_video_decoder_proxy.cc',
         'proxy/ppb_video_decoder_proxy.h',
+        'proxy/ppb_x509_certificate_private_proxy.cc',
+        'proxy/ppb_x509_certificate_private_proxy.h',
         'proxy/ppp_class_proxy.cc',
         'proxy/ppp_class_proxy.h',
         'proxy/ppp_graphics_3d_proxy.cc',
         'proxy/ppp_graphics_3d_proxy.h',
         'proxy/ppp_input_event_proxy.cc',
         'proxy/ppp_input_event_proxy.h',
         'proxy/ppp_instance_private_proxy.cc',
         'proxy/ppp_instance_private_proxy.h',
         'proxy/ppp_instance_proxy.cc',
         'proxy/ppp_instance_proxy.h',
@@ skipping 22 matching lines @@
         'proxy/serialized_var.cc',
         'proxy/serialized_var.h',
         'proxy/var_serialization_rules.h',
       ],
       'defines': [
         'PPAPI_PROXY_IMPLEMENTATION',
       ],
     },
   ],
 }