Prefer ScopedNestableTaskAllower over manual save/restore

webkit/plugins/ppapi/plugin_module.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 "webkit/plugins/ppapi/plugin_module.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 193 matching lines @@
                       PP_Resource image,
                       const PP_Point* top_left) {
   EnterResource<PPB_Graphics2D_API> enter(device_context_2d, true);
   if (enter.failed())
     return PP_FALSE;
   return BoolToPPBool(static_cast<PPB_Graphics2D_Impl*>(enter.object())->
       ReadImageData(image, top_left));
 }
 
 void RunMessageLoop(PP_Instance instance) {
-  bool old_state = MessageLoop::current()->NestableTasksAllowed();
-  MessageLoop::current()->SetNestableTasksAllowed(true);
+  MessageLoop::ScopedNestableTaskAllower allow(MessageLoop::current());
   MessageLoop::current()->Run();
-  MessageLoop::current()->SetNestableTasksAllowed(old_state);
 }
 
 void QuitMessageLoop(PP_Instance instance) {
   MessageLoop::current()->QuitNow();
 }
 
 uint32_t GetLiveObjectsForInstance(PP_Instance instance_id) {
   return HostGlobals::Get()->GetResourceTracker()->GetLiveObjectsForInstance(
       instance_id);
 }
@@ skipping 373 matching lines @@
   int retval = entry_points.initialize_module(pp_module(), &GetInterface);
   if (retval != 0) {
     LOG(WARNING) << "PPP_InitializeModule returned failure " << retval;
     return false;
   }
   return true;
 }
 
 }  // namespace ppapi
 }  // namespace webkit