Use auto and Range-based loop interation in Source/core/dom/custom/

Source/core/dom/custom/CustomElementMicrotaskDispatcher.cpp

 // Copyright 2014 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 "config.h"
 #include "core/dom/custom/CustomElementMicrotaskDispatcher.h"
 
 #include "core/dom/Microtask.h"
 #include "core/dom/custom/CustomElementCallbackQueue.h"
 #include "core/dom/custom/CustomElementMicrotaskImportStep.h"
@@ skipping 53 matching lines @@
     m_hasScheduledMicrotask = false;
 
     // Finishing microtask work deletes all
     // CustomElementCallbackQueues. Being in a callback delivery scope
     // implies those queues could still be in use.
     ASSERT_WITH_SECURITY_IMPLICATION(!CustomElementProcessingStack::inCallbackDeliveryScope());
 
     m_phase = Resolving;
 
     m_phase = DispatchingCallbacks;
-    for (WillBeHeapVector<RawPtrWillBeMember<CustomElementCallbackQueue> >::iterator it = m_elements.begin(); it != m_elements.end(); ++it) {
+    for (const auto& element : m_elements) {
         // Created callback may enqueue an attached callback.
         CustomElementProcessingStack::CallbackDeliveryScope scope;
-        (*it)->processInElementQueue(kMicrotaskQueueId);
+        element->processInElementQueue(kMicrotaskQueueId);
     }
 
     m_elements.clear();
     CustomElementScheduler::microtaskDispatcherDidFinish();
     m_phase = Quiescent;
 }
 
 void CustomElementMicrotaskDispatcher::trace(Visitor* visitor)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_elements);
 #endif
 }
 
 } // namespace blink