Make textContent trigger single DOMSubtreeModified event

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 60e09a205ed5da49f28b78bc9f696885e66f7f40..62bbf79145d2778196f3a4cb68ee5854b0c90d27 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -1401,10 +1401,11 @@ void Node::setTextContent(const String& text)
                 return;
 
             ChildListMutationScope mutation(*this);
-            container->removeChildren();
+            bool emptyText = text.isEmpty();
+            container->removeChildren(emptyText);
             // Note: This API will not insert empty text nodes:
             // http://dom.spec.whatwg.org/#dom-node-textcontent
-            if (!text.isEmpty())
+            if (!emptyText)
                 container->appendChild(document().createTextNode(text), ASSERT_NO_EXCEPTION);
             return;
         }