Remove some unused functions in core

Source/core/dom/custom/CustomElementMicrotaskRunQueue.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/CustomElementMicrotaskRunQueue.h"
 
 #include "core/dom/Microtask.h"
 #include "core/dom/custom/CustomElementAsyncImportMicrotaskQueue.h"
 #include "core/dom/custom/CustomElementSyncMicrotaskQueue.h"
@@ skipping 53 matching lines @@
     m_syncQueue->dispatch();
     if (m_syncQueue->isEmpty())
         m_asyncQueue->dispatch();
 }
 
 bool CustomElementMicrotaskRunQueue::isEmpty() const
 {
     return m_syncQueue->isEmpty() && m_asyncQueue->isEmpty();
 }
 
-#if !defined(NDEBUG)
-void CustomElementMicrotaskRunQueue::show(unsigned indent)
-{
-    fprintf(stderr, "Sync:\n");
-    m_syncQueue->show(indent);
-    fprintf(stderr, "Async:\n");
-    m_asyncQueue->show(indent);
-}
-#endif
-
 } // namespace blink