Support LoadSession() in MediaKeys and PPP_ContentDecryptor_Private interface.

ppapi/proxy/ppp_content_decryptor_private_proxy.h

Index: ppapi/proxy/ppp_content_decryptor_private_proxy.h
diff --git a/ppapi/proxy/ppp_content_decryptor_private_proxy.h b/ppapi/proxy/ppp_content_decryptor_private_proxy.h
index dfbcf4f5d42806e575ea56395595266a83220d5b..2ed248477d9100b22158323b8032701d65e82ab4 100644
--- a/ppapi/proxy/ppp_content_decryptor_private_proxy.h
+++ b/ppapi/proxy/ppp_content_decryptor_private_proxy.h
@@ -34,8 +34,11 @@ class PPP_ContentDecryptor_Private_Proxy : public InterfaceProxy {
                        SerializedVarReceiveInput key_system);
   void OnMsgCreateSession(PP_Instance instance,
                           uint32_t session_id,
-                          SerializedVarReceiveInput type,
+                          SerializedVarReceiveInput content_type,
                           SerializedVarReceiveInput init_data);
+  void OnMsgLoadSession(PP_Instance instance,
+                        uint32_t session_id,
+                        SerializedVarReceiveInput web_session_id);
   void OnMsgUpdateSession(PP_Instance instance,
                           uint32_t session_id,
                           SerializedVarReceiveInput response);