Use C++11 range-based loop for core/clipboard, core/dom and core/testing

Source/core/dom/MutationObserverRegistration.cpp

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 79 matching lines @@
     m_transientRegistrationNodes->add(&node);
 }
 
 void MutationObserverRegistration::clearTransientRegistrations()
 {
     if (!m_transientRegistrationNodes) {
         ASSERT(!m_registrationNodeKeepAlive);
         return;
     }
 
-    for (NodeHashSet::iterator iter = m_transientRegistrationNodes->begin(); iter != m_transientRegistrationNodes->end(); ++iter)
-        (*iter)->unregisterTransientMutationObserver(this);
+    for (auto& node : *m_transientRegistrationNodes)
+        node->unregisterTransientMutationObserver(this);
 
     m_transientRegistrationNodes.clear();
 
     ASSERT(m_registrationNodeKeepAlive);
     m_registrationNodeKeepAlive = nullptr; // Balanced in observeSubtreeNodeWillDetach.
 }
 
 void MutationObserverRegistration::unregister()
 {
     ASSERT(m_registrationNode);
@@ skipping 33 matching lines @@
 {
     visitor->trace(m_observer);
     visitor->trace(m_registrationNode);
     visitor->trace(m_registrationNodeKeepAlive);
 #if ENABLE(OILPAN)
     visitor->trace(m_transientRegistrationNodes);
 #endif
 }
 
 } // namespace blink