removeBetween() -> detach() performance fix.

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

Index: third_party/WebKit/Source/core/dom/ContainerNode.cpp
diff --git a/third_party/WebKit/Source/core/dom/ContainerNode.cpp b/third_party/WebKit/Source/core/dom/ContainerNode.cpp
index 832952dc10b03caca5e147001b3f0f4e2251245a..a95f105f903ec5b50c5f135e1d647e9341c7c68e 100644
--- a/third_party/WebKit/Source/core/dom/ContainerNode.cpp
+++ b/third_party/WebKit/Source/core/dom/ContainerNode.cpp
@@ -606,8 +606,10 @@ void ContainerNode::removeBetween(Node* previousChild, Node* nextChild, Node& ol
 
     AttachContext context;
     context.clearInvalidation = true;
-    if (!needsAttach() || !oldChild.needsAttach())
+    if (!oldChild.needsAttach())
         oldChild.detach(context);
+    else if (oldChild.needsStyleInvalidation())
+        document().styleEngine().styleInvalidator().clearInvalidation(toElement(oldChild));

[esprehn, 2016/01/15 00:31:45]

can Element::removedFrom do this? It seems like it belongs there with the other
Element clean up code.

[rune, 2016/01/15 09:42:41]

Yeah, I think so. It means it'll check needsStyleInvalidation() both in detach()
and removedFrom(), for the non-root elements, in the case where we're removing
the element from the document, but that's probably ok (clearInvalidation() only
called once, of course).

[rune, 2016/01/15 13:25:41]

Done.

 
     if (nextChild)
         nextChild->setPreviousSibling(previousChild);