Revert of Introduce SynchronousMutationObserver::didChangeAttribute()

third_party/WebKit/Source/core/dom/SynchronousMutationNotifier.cpp

 // Copyright 2016 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 "core/dom/SynchronousMutationNotifier.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/SynchronousMutationObserver.h"
 
 namespace blink {
 
 SynchronousMutationNotifier::SynchronousMutationNotifier() = default;
 
-void SynchronousMutationNotifier::notifyChangeAttribute(
-    const Element& element) {
-  for (SynchronousMutationObserver* observer : m_observers)
-    observer->didChangeAttribute(element);
-}
-
 void SynchronousMutationNotifier::notifyChangeChildren(
     const ContainerNode& container) {
   for (SynchronousMutationObserver* observer : m_observers)
     observer->didChangeChildren(container);
 }
 
 void SynchronousMutationNotifier::notifyMergeTextNodes(
     const Text& node,
     const NodeWithIndex& nodeToBeRemovedWithIndex,
     unsigned oldLength) {
@@ skipping 28 matching lines @@
   for (SynchronousMutationObserver* observer : m_observers)
     observer->nodeChildrenWillBeRemoved(container);
 }
 
 void SynchronousMutationNotifier::notifyNodeWillBeRemoved(Node& node) {
   for (SynchronousMutationObserver* observer : m_observers)
     observer->nodeWillBeRemoved(node);
 }
 
 }  // namespace blink