Make textContent trigger single DOMSubtreeModified event

Source/core/dom/ContainerNode.cpp

Index: Source/core/dom/ContainerNode.cpp
diff --git a/Source/core/dom/ContainerNode.cpp b/Source/core/dom/ContainerNode.cpp
index e9864bcd16ca9fb5d54ccd980cf004b0762e994c..75f7f4121ea9b502b41dbbcbd7bfe13b52734ce5 100644
--- a/Source/core/dom/ContainerNode.cpp
+++ b/Source/core/dom/ContainerNode.cpp
@@ -618,7 +618,7 @@ void ContainerNode::parserRemoveChild(Node& oldChild)
 
 // 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;
@@ -671,10 +671,7 @@ void ContainerNode::removeChildren()
         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();
 }