Make textContent trigger single DOMSubtreeModified event

Source/core/dom/ContainerNode.cpp

 /*
  * 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, 2008, 2009, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 600 matching lines @@
     oldChild.notifyMutationObserversNodeWillDetach();
 
     removeBetween(prev, next, oldChild);
 
     notifyNodeRemoved(oldChild);
     childrenChanged(ChildrenChange::forRemoval(oldChild, prev, next, ChildrenChangeSourceParser));
 }
 
 // This differs from other remove functions because it forcibly removes all the children,
 // regardless of read-only status or event exceptions, e.g.
-void ContainerNode::removeChildren()
+void ContainerNode::removeChildren(SubtreeModificationAction action)
 {
     if (!m_firstChild)
         return;
 
     // The container node can be removed from event handlers.
     RefPtrWillBeRawPtr<ContainerNode> protect(this);
 
     // Do any prep work needed before actually starting to detach
     // and remove... e.g. stop loading frames, fire unload events.
     willRemoveChildren();
@@ skipping 32 matching lines @@
                 removeBetween(0, child->nextSibling(), *child);
                 removedChildren.append(child.get());
                 notifyNodeRemoved(*child);
             }
         }
 
         ChildrenChange change = {AllChildrenRemoved, nullptr, nullptr, ChildrenChangeSourceAPI};
         childrenChanged(change);
     }
 
-    // We don't fire the DOMSubtreeModified event for Attr Nodes. This matches the behavior
-    // of IE and Firefox. This event is fired synchronously and is a source of trouble for
-    // attributes as the JS callback could alter the attributes and leave us in a bad state.
-    if (!isAttributeNode())
+    if (action == DispatchSubtreeModifiedEvent)
         dispatchSubtreeModifiedEvent();
 }
 
 PassRefPtrWillBeRawPtr<Node> ContainerNode::appendChild(PassRefPtrWillBeRawPtr<Node> newChild, ExceptionState& exceptionState)
 {
     RefPtrWillBeRawPtr<ContainerNode> protect(this);
 
 #if !ENABLE(OILPAN)
     // Check that this node is not "floating".
     // If it is, it can be deleted as a side effect of sending mutation events.
@@ skipping 753 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace blink