Add PPAPI C++ wrappers for PDF.

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 275 matching lines @@
       'cpp/private/host_resolver_private.cc',
       'cpp/private/host_resolver_private.h',
       'cpp/private/instance_private.cc',
       'cpp/private/instance_private.h',
       'cpp/private/net_address_private.cc',
       'cpp/private/net_address_private.h',
       'cpp/private/network_list_private.cc',
       'cpp/private/network_list_private.h',
       'cpp/private/network_monitor_private.cc',
       'cpp/private/network_monitor_private.h',
+      'cpp/private/pdf.cc',
+      'cpp/private/pdf.h',
       'cpp/private/tcp_server_socket_private.cc',
       'cpp/private/tcp_server_socket_private.h',
       'cpp/private/tcp_socket_private.cc',
       'cpp/private/tcp_socket_private.h',
       'cpp/private/udp_socket_private.cc',
       'cpp/private/udp_socket_private.h',
       'cpp/private/var_private.cc',
       'cpp/private/var_private.h',
       'cpp/private/x509_certificate_private.cc',
       'cpp/private/x509_certificate_private.h',
@@ skipping 190 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',
     ],
   },
 }