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

ppapi/proxy/ppb_var_deprecated_proxy.cc

 // 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.
 
 #include "ppapi/proxy/ppb_var_deprecated_proxy.h"
 
 #include <stdlib.h>  // For malloc
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "ppapi/c/dev/ppb_var_deprecated.h"
 #include "ppapi/c/pp_var.h"
 #include "ppapi/c/ppb_var.h"
 #include "ppapi/c/ppb_core.h"
 #include "ppapi/proxy/host_dispatcher.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_globals.h"
 #include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/proxy/plugin_var_tracker.h"
+#include "ppapi/proxy/proxy_object_var.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppp_class_proxy.h"
 #include "ppapi/proxy/serialized_var.h"
 #include "ppapi/shared_impl/ppb_var_shared.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/shared_impl/var.h"
 
 namespace ppapi {
 namespace proxy {
 
@@ skipping 216 matching lines @@
 }
 
 PP_Var CreateObject(PP_Instance instance,
                     const PPP_Class_Deprecated* ppp_class,
                     void* ppp_class_data) {
   ProxyAutoLock lock;
   Dispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
   if (!dispatcher)
     return PP_MakeUndefined();
 
+  PluginVarTracker* tracker = PluginGlobals::Get()->plugin_var_tracker();
+  if (tracker->IsPluginImplementedObjectAlive(ppp_class_data))
+    return PP_MakeUndefined();  // Object already exists with this user data.
+
   ReceiveSerializedVarReturnValue result;
   int64 class_int = static_cast<int64>(reinterpret_cast<intptr_t>(ppp_class));
   int64 data_int =
       static_cast<int64>(reinterpret_cast<intptr_t>(ppp_class_data));
   dispatcher->Send(new PpapiHostMsg_PPBVar_CreateObjectDeprecated(
       API_ID_PPB_VAR_DEPRECATED, instance, class_int, data_int,
       &result));
-  return result.Return(dispatcher);
+  PP_Var ret_var = result.Return(dispatcher);
+
+  // Register this object as being implemented by the plugin.
+  tracker->PluginImplementedObjectCreated(instance, ret_var,
+                                          ppp_class, ppp_class_data);
+  return ret_var;
 }
 
 InterfaceProxy* CreateVarDeprecatedProxy(Dispatcher* dispatcher) {
   return new PPB_Var_Deprecated_Proxy(dispatcher );
 }
 
 }  // namespace
 
 PPB_Var_Deprecated_Proxy::PPB_Var_Deprecated_Proxy(
     Dispatcher* dispatcher)
@@ skipping 238 matching lines @@
 }
 
 void PPB_Var_Deprecated_Proxy::DoReleaseObject(int64 object_id) {
   PP_Var var = { PP_VARTYPE_OBJECT };
   var.value.as_id = object_id;
   ppb_var_impl_->Release(var);
 }
 
 }  // namespace proxy
 }  // namespace ppapi