Call Element::rebuildLayoutTree from Document::updateStyle directly

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 207659d70f65cfdf3da66036ac30f8ba15cce0d2..a0e874a314b9761c50faf43deb44540d829dc37a 100644
--- a/third_party/WebKit/Source/core/dom/ContainerNode.cpp
+++ b/third_party/WebKit/Source/core/dom/ContainerNode.cpp
@@ -266,8 +266,6 @@ class ContainerNode::AdoptAndAppendChild {
 Node* ContainerNode::insertBefore(Node* newChild,
                                   Node* refChild,
                                   ExceptionState& exceptionState) {
-  // https://dom.spec.whatwg.org/#concept-node-pre-insert
-
   // insertBefore(node, 0) is equivalent to appendChild(node)
   if (!refChild)
     return appendChild(newChild, exceptionState);
@@ -286,12 +284,9 @@ Node* ContainerNode::insertBefore(Node* newChild,
     return nullptr;
   }
 
-  // 3. If reference child is node, set it to node’s next sibling.
-  if (refChild == newChild) {
-    refChild = newChild->nextSibling();
-    if (!refChild)
-      return appendChild(newChild, exceptionState);
-  }
+  // Nothing to do.
+  if (refChild->previousSibling() == newChild || refChild == newChild)
+    return newChild;
 
   NodeVector targets;
   if (!collectChildrenAndRemoveFromOldParentWithCheck(
@@ -396,7 +391,8 @@ void ContainerNode::parserInsertBefore(Node* newChild, Node& nextChild) {
 Node* ContainerNode::replaceChild(Node* newChild,
                                   Node* oldChild,
                                   ExceptionState& exceptionState) {
-  // https://dom.spec.whatwg.org/#concept-node-replace
+  if (oldChild == newChild)  // Nothing to do.
+    return oldChild;
 
   if (!oldChild) {
     exceptionState.throwDOMException(NotFoundError,
@@ -416,23 +412,17 @@ Node* ContainerNode::replaceChild(Node* newChild,
   }
 
   ChildListMutationScope mutation(*this);
-  // 7. Let reference child be child’s next sibling.
   Node* next = oldChild->nextSibling();
-  // 8. If reference child is node, set it to node’s next sibling.
-  if (next == newChild)
-    next = newChild->nextSibling();
-
-  // TODO(tkent): According to the specification, we should remove |newChild|
-  // from its parent here, and create a separated mutation record for it.
-  // Refer to imported/wpt/dom/nodes/MutationObserver-childList.html.
 
-  // 12. If child’s parent is not null, run these substeps:
-  //    1. Set removedNodes to a list solely containing child.
-  //    2. Remove child from its parent with the suppress observers flag set.
+  // Remove the node we're replacing.
   removeChild(oldChild, exceptionState);
   if (exceptionState.hadException())
     return nullptr;
 
+  if (next && (next->previousSibling() == newChild ||
+               next == newChild))  // nothing to do
+    return oldChild;
+
   // Does this one more time because removeChild() fires a MutationEvent.
   if (!checkAcceptChild(newChild, oldChild, exceptionState))
     return oldChild;
@@ -659,6 +649,9 @@ Node* ContainerNode::appendChild(Node* newChild,
     return newChild;
   DCHECK(newChild);
 
+  if (newChild == m_lastChild)  // nothing to do
+    return newChild;
+
   NodeVector targets;
   if (!collectChildrenAndRemoveFromOldParentWithCheck(
           nullptr, nullptr, *newChild, targets, exceptionState))
@@ -766,10 +759,6 @@ void ContainerNode::attachLayoutTree(const AttachContext& context) {
   childrenContext.resolvedStyle = nullptr;
 
   for (Node* child = firstChild(); child; child = child->nextSibling()) {
-#if DCHECK_IS_ON()
-    DCHECK(child->needsAttach() ||
-           childAttachedAllowedWhenAttachingChildren(this));

[esprehn, 2017/02/13 22:19:41]

Lets add this back?

[nainar, 2017/02/14 03:42:08]

Done.

-#endif
     if (child->needsAttach())
       child->attachLayoutTree(childrenContext);
   }
@@ -1280,7 +1269,6 @@ void ContainerNode::setRestyleFlag(DynamicRestyleFlags mask) {
 void ContainerNode::recalcDescendantStyles(StyleRecalcChange change) {
   DCHECK(document().inStyleRecalc());
   DCHECK(change >= UpdatePseudoElements || childNeedsStyleRecalc());
-  DCHECK(!needsStyleRecalc());

[esprehn, 2017/02/13 22:19:41]

ditto

[nainar, 2017/02/14 03:42:08]

This information isn't true anymore. We are retaining the needsStyleRecalc
information

 
   // This loop is deliberately backwards because we use insertBefore in the
   // layout tree, and want to avoid a potentially n^2 loop to find the insertion
@@ -1305,6 +1293,25 @@ void ContainerNode::recalcDescendantStyles(StyleRecalcChange change) {
   }
 }
 
+void ContainerNode::rebuildChildrenLayoutTrees() {
+  DCHECK(!needsReattachLayoutTree());
+
+  for (Node* child = lastChild(); child; child = child->previousSibling()) {
+    if (child->needsReattachLayoutTree() ||
+        child->childNeedsReattachLayoutTree()) {
+      if (child->isTextNode())
+        toText(child)->rebuildTextLayoutTree();
+      else if (child->isElementNode())
+        toElement(child)->rebuildLayoutTree();
+    }
+  }
+  clearNeedsStyleRecalc();
+  // This is done in ContainerNode::attachLayoutTree but will never be cleared
+  // if we don't enter ContainerNode::attachLayoutTree so we do it here.
+  clearChildNeedsStyleRecalc();
+  clearChildNeedsReattachLayoutTree();
+}
+
 void ContainerNode::checkForSiblingStyleChanges(SiblingCheckType changeType,
                                                 Element* changedElement,
                                                 Node* nodeBeforeChange,