Reattach whitespace siblings only when needed

Source/core/dom/RenderTreeBuilder.h

 /*
  * 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, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 27 matching lines @@
 class RenderObject;
 class RenderStyle;
 
 class RenderTreeBuilder {
     STACK_ALLOCATED();
 public:
     RenderTreeBuilder(Node* node)
         : m_node(node)
         , m_renderingParent(NodeRenderingTraversal::parent(node))
     {
-        ASSERT(node->needsAttach());
         ASSERT(node->document().inStyleRecalc());
 
         // FIXME: We should be able to ASSERT(node->inActiveDocument()) but childrenChanged is called
         // before ChildNodeInsertionNotifier in ContainerNode's methods and some implementations
         // will trigger a layout inside childrenChanged.
         // Mainly HTMLTextAreaElement::childrenChanged calls HTMLTextFormControlElement::setSelectionRange
         // which does an updateLayoutIgnorePendingStylesheets.
     }
 
     void createRendererIfNeeded();
@@ skipping 28 matching lines @@
     RenderTreeBuilderForText(Text* text)
         : RenderTreeBuilder(text) { }
 
     virtual void createRenderer() override final;
     virtual bool rendererIsNeeded() const override final;
 };
 
 } // namespace blink
 
 #endif