Pepper: Simplify idl_thunk implementation.

ppapi/thunk/ppb_messaging_thunk.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.
 
-// From ppb_messaging.idl modified Thu Mar 28 11:12:59 2013.
+// From ppb_messaging.idl modified Tue Apr 16 11:25:44 2013.
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_messaging.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_instance_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 #include "ppapi/thunk/thunk.h"
 
 namespace ppapi {
 namespace thunk {
 
 namespace {
 
 void PostMessage(PP_Instance instance, struct PP_Var message) {
   VLOG(4) << "PPB_Messaging::PostMessage()";
   EnterInstance enter(instance);
-  if (enter.succeeded())
-    enter.functions()->PostMessage(instance, message);
+  if (enter.failed())
+    return;
+  enter.functions()->PostMessage(instance, message);
 }
 
 const PPB_Messaging_1_0 g_ppb_messaging_thunk_1_0 = {
   &PostMessage
 };
 
 }  // namespace
 
 const PPB_Messaging_1_0* GetPPB_Messaging_1_0_Thunk() {
   return &g_ppb_messaging_thunk_1_0;
 }
 
 }  // namespace thunk
 }  // namespace ppapi