Use C++11 features in core/workers.

Source/core/workers/WorkerEventQueue.cpp

 /*
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 118 matching lines @@
     if (!task)
         return false;
     task->cancel();
     removeEvent(event);
     return true;
 }
 
 void WorkerEventQueue::close()
 {
     m_isClosed = true;
-    for (EventTaskMap::iterator it = m_eventTaskMap.begin(); it != m_eventTaskMap.end(); ++it) {
-        Event* event = it->key.get();
-        EventDispatcherTask* task = it->value;
+    for (const auto& entry : m_eventTaskMap) {
+        Event* event = entry.key.get();
+        EventDispatcherTask* task = entry.value;
         InspectorInstrumentation::didRemoveEvent(event->target(), event);
         task->cancel();
     }
     m_eventTaskMap.clear();
 }
 
 }