Call Element::rebuildLayoutTree from Document::updateStyle directly

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

Index: third_party/WebKit/Source/core/dom/Node.cpp
diff --git a/third_party/WebKit/Source/core/dom/Node.cpp b/third_party/WebKit/Source/core/dom/Node.cpp
index aeaa766772c025ce7febc7821a9155f978936b3d..dc0d0bf5fea87f609793a420e09717e859276ee0 100644
--- a/third_party/WebKit/Source/core/dom/Node.cpp
+++ b/third_party/WebKit/Source/core/dom/Node.cpp
@@ -880,24 +880,31 @@ Node* Node::commonAncestor(const Node& other,
 }
 
 void Node::reattachLayoutTree(const AttachContext& context) {
+  DCHECK(!needsStyleRecalc());
+  DCHECK(!childNeedsStyleRecalc());
   AttachContext reattachContext(context);
   reattachContext.performingReattach = true;
 
   // We only need to detach if the node has already been through
   // attachLayoutTree().
-  if (getStyleChangeType() < NeedsReattachStyleChange)
+  if (getStyleChangeType() <= SubtreeStyleChange)

[nainar, 2016/11/29 06:13:39]

Question: This will always be true since SubtreeStyleChange is the max value you
can set StyleChangeType to be now. Should this be ommitted now? Or replaced with
!needsReattachLayoutTree()

[rune, 2016/12/05 10:05:17]

Yes, this test doesn't make sense now. If you setNeedsReattachLayoutTree() in
detachLayoutTree(), the check here should probably be
!needsReattachLayoutTree(), yes.

     detachLayoutTree(reattachContext);
   attachLayoutTree(reattachContext);
+  DCHECK(!needsStyleRecalc());
+  DCHECK(!needsReattachLayoutTree());
 }
 
 void Node::attachLayoutTree(const AttachContext&) {
   DCHECK(document().inStyleRecalc() || isDocumentNode());
   DCHECK(!document().lifecycle().inDetach());
-  DCHECK(needsAttach());
+  DCHECK(needsReattachLayoutTree());
   DCHECK(!layoutObject() ||
          (layoutObject()->style() &&
           (layoutObject()->parent() || layoutObject()->isLayoutView())));
 
+  // Only doing this to cater to the comment in
+  // Document::updateStyleAndLayoutTree() right above the call to
+  // Document::updateStyle().
   clearNeedsStyleRecalc();
   clearNeedsReattachLayoutTree();
 
@@ -912,7 +919,7 @@ void Node::detachLayoutTree(const AttachContext& context) {
   if (layoutObject())
     layoutObject()->destroyAndCleanupAnonymousWrappers();
   setLayoutObject(nullptr);
-  setStyleChange(NeedsReattachStyleChange);
+  setNeedsReattachLayoutTree();

[nainar, 2016/11/29 06:13:39]

Set the relevant NeedsReattachLayoutTree flag. 

   clearChildNeedsStyleInvalidation();
 }