SELECT element: Do not update popup content if CharacterData or attribute value is not changed.

third_party/WebKit/Source/core/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
@@ skipping 24 matching lines @@
 #include "bindings/core/v8/HTMLElementOrLong.h"
 #include "bindings/core/v8/HTMLOptionElementOrHTMLOptGroupElement.h"
 #include "core/HTMLNames.h"
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/Attribute.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExecutionContextTask.h"
 #include "core/dom/MutationCallback.h"
 #include "core/dom/MutationObserver.h"
 #include "core/dom/MutationObserverInit.h"
+#include "core/dom/MutationRecord.h"
 #include "core/dom/NodeComputedStyle.h"
 #include "core/dom/NodeListsNodeData.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/events/GestureEvent.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
 #include "core/events/ScopedEventQueue.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 1905 matching lines @@
 // PopupUpdater notifies updates of the specified SELECT element subtree to
 // a PopupMenu object.
 class HTMLSelectElement::PopupUpdater : public MutationCallback {
  public:
   explicit PopupUpdater(HTMLSelectElement&);
   DECLARE_VIRTUAL_TRACE();
 
   void dispose() { m_observer->disconnect(); }
 
  private:
-  void call(const HeapVector<Member<MutationRecord>>&,
+  void call(const HeapVector<Member<MutationRecord>>& records,
             MutationObserver*) override {
     // We disconnect the MutationObserver when a popuup is closed.  However
     // MutationObserver can call back after disconnection.
     if (!m_select->popupIsVisible())
       return;
-    m_select->didMutateSubtree();
+    for (const auto& record : records) {
+      if (record->type() == "attributes") {
+        const Element& element = *toElement(record->target());
+        if (record->oldValue() == element.getAttribute(record->attributeName()))
+          continue;
+      } else if (record->type() == "characterData") {
+        if (record->oldValue() == record->target()->nodeValue())
+          continue;
+      }
+      m_select->didMutateSubtree();
+      return;
+    }
   }
 
   ExecutionContext* getExecutionContext() const override {
     return &m_select->document();
   }
 
   Member<HTMLSelectElement> m_select;
   Member<MutationObserver> m_observer;
 };
 
 HTMLSelectElement::PopupUpdater::PopupUpdater(HTMLSelectElement& select)
     : m_select(select) {
   m_observer = MutationObserver::create(this);
   Vector<String> filter;
   filter.reserveCapacity(4);
   // Observe only attributes which affect popup content.
   filter.append(String("disabled"));
   filter.append(String("label"));
   filter.append(String("selected"));
   filter.append(String("value"));
   MutationObserverInit init;
+  init.setAttributeOldValue(true);
   init.setAttributes(true);
   init.setAttributeFilter(filter);
   init.setCharacterData(true);
+  init.setCharacterDataOldValue(true);
   init.setChildList(true);
   init.setSubtree(true);
   m_observer->observe(&select, init, ASSERT_NO_EXCEPTION);
 }
 
 DEFINE_TRACE(HTMLSelectElement::PopupUpdater) {
   visitor->trace(m_select);
   visitor->trace(m_observer);
   MutationCallback::trace(visitor);
 }
@@ skipping 10 matching lines @@
   m_popupUpdater = nullptr;
 }
 
 void HTMLSelectElement::didMutateSubtree() {
   DCHECK(popupIsVisible());
   DCHECK(m_popup);
   m_popup->updateFromElement(PopupMenu::ByDOMChange);
 }
 
 }  // namespace blink