Actually free plugin implement vars when running out of process when the

ppapi/proxy/proxy_object_var.cc

 // Copyright (c) 2011 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.
 
 #include "ppapi/proxy/proxy_object_var.h"
 
 #include "base/logging.h"
 #include "ppapi/c/pp_var.h"
 
 using ppapi::proxy::PluginDispatcher;
 
 namespace ppapi {
 
 ProxyObjectVar::ProxyObjectVar(PluginDispatcher* dispatcher,
                                int32 host_var_id)
     : dispatcher_(dispatcher),
-      host_var_id_(host_var_id) {
+      host_var_id_(host_var_id),
+      user_data_(NULL) {
   // Should be given valid objects or we'll crash later.
-  DCHECK(dispatcher_);
   DCHECK(host_var_id_);
 }
 
 ProxyObjectVar::~ProxyObjectVar() {
 }
 
 ProxyObjectVar* ProxyObjectVar::AsProxyObjectVar() {
   return this;
 }
 
 PP_VarType ProxyObjectVar::GetType() const {
   return PP_VARTYPE_OBJECT;
 }
 
 void ProxyObjectVar::AssignVarID(int32 id) {
   return Var::AssignVarID(id);
 }
 
 }  // namespace ppapi