Call Element::rebuildLayoutTree from Document::updateStyle directly

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  *
@@ skipping 885 matching lines @@
   DCHECK(!otherIterator);
   return nullptr;
 }
 
 void Node::reattachLayoutTree(const AttachContext& context) {
   AttachContext reattachContext(context);
   reattachContext.performingReattach = true;
 
   // We only need to detach if the node has already been through
   // attachLayoutTree().
   if (getStyleChangeType() < NeedsReattachStyleChange)

[nainar, 2017/02/02 07:42:01]

Figured out why tests were failing!  

This check here will always be true if I call clearNeedsStyleRecalc() in
Element::recalcStyle() (which clears the styleChangeType making it always less
than NeedsReattachStyleChange) due to which we are performing detachLayoutTree()
in more cases than is necessary. 

So looks like I can't clear that flag there. Working on this now. Will have a
patch up soon once I make sure all the asserts are in order. Just posting an
update here.

     detachLayoutTree(reattachContext);
   attachLayoutTree(reattachContext);
 }
 
 void Node::attachLayoutTree(const AttachContext&) {
   DCHECK(document().inStyleRecalc() || isDocumentNode());
   DCHECK(!document().lifecycle().inDetach());
   DCHECK(needsAttach());
   DCHECK(!layoutObject() ||
          (layoutObject()->style() &&
           (layoutObject()->parent() || layoutObject()->isLayoutView())));
 
   clearNeedsStyleRecalc();
   clearNeedsReattachLayoutTree();
 
   if (AXObjectCache* cache = document().axObjectCache())
     cache->updateCacheAfterNodeIsAttached(this);
 }
 
 void Node::detachLayoutTree(const AttachContext& context) {
   DCHECK(document().lifecycle().stateAllowsDetach());
   DocumentLifecycle::DetachScope willDetach(document().lifecycle());
 
   if (layoutObject())
     layoutObject()->destroyAndCleanupAnonymousWrappers();
   setLayoutObject(nullptr);
   setStyleChange(NeedsReattachStyleChange);
+  setFlag(NeedsReattachLayoutTree);
   clearChildNeedsStyleInvalidation();
 }
 
 void Node::reattachWhitespaceSiblingsIfNeeded(Text* start) {
   ScriptForbiddenScope forbidScriptDuringRawIteration;
   for (Node* sibling = start; sibling; sibling = sibling->nextSibling()) {
     if (sibling->isTextNode() && toText(sibling)->containsOnlyWhitespace()) {
       bool hadLayoutObject = !!sibling->layoutObject();
       toText(sibling)->reattachLayoutTreeIfNeeded();
       // If sibling's layout object status didn't change we don't need to
@@ skipping 1622 matching lines @@
   if (node) {
     std::stringstream stream;
     node->printNodePathTo(stream);
     LOG(INFO) << stream.str();
   } else {
     LOG(INFO) << "Cannot showNodePath for <null>";
   }
 }
 
 #endif