Cleanup: Only need one bit (not two) to express flow thread state.

Source/core/dom/LayoutTreeBuilder.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, 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 114 matching lines @@
 
     LayoutObject* parentLayoutObject = this->parentLayoutObject();
 
     if (!parentLayoutObject->isChildAllowed(newLayoutObject, style)) {
         newLayoutObject->destroy();
         return;
     }
 
     // Make sure the LayoutObject already knows it is going to be added to a LayoutFlowThread before we set the style
     // for the first time. Otherwise code using inLayoutFlowThread() in the styleWillChange and styleDidChange will fail.
-    newLayoutObject->setFlowThreadState(parentLayoutObject->flowThreadState());
+    newLayoutObject->setIsInsideFlowThread(parentLayoutObject->isInsideFlowThread());
 
     LayoutObject* nextLayoutObject = this->nextLayoutObject();
     m_node->setLayoutObject(newLayoutObject);
     newLayoutObject->setStyle(&style); // setStyle() can depend on layoutObject() already being set.
 
     if (Fullscreen::isActiveFullScreenElement(*m_node)) {
         newLayoutObject = LayoutFullScreen::wrapLayoutObject(newLayoutObject, parentLayoutObject, &m_node->document());
         if (!newLayoutObject)
             return;
     }
@@ skipping 10 matching lines @@
     ASSERT(m_node->textLayoutObjectIsNeeded(style, *parentLayoutObject));
 
     LayoutText* newLayoutObject = m_node->createTextLayoutObject(style);
     if (!parentLayoutObject->isChildAllowed(newLayoutObject, style)) {
         newLayoutObject->destroy();
         return;
     }
 
     // Make sure the LayoutObject already knows it is going to be added to a LayoutFlowThread before we set the style
     // for the first time. Otherwise code using inLayoutFlowThread() in the styleWillChange and styleDidChange will fail.
-    newLayoutObject->setFlowThreadState(parentLayoutObject->flowThreadState());
+    newLayoutObject->setIsInsideFlowThread(parentLayoutObject->isInsideFlowThread());
 
     LayoutObject* nextLayoutObject = this->nextLayoutObject();
     m_node->setLayoutObject(newLayoutObject);
     // Parent takes care of the animations, no need to call setAnimatableStyle.
     newLayoutObject->setStyle(&style);
     parentLayoutObject->addChild(newLayoutObject, nextLayoutObject);
 }
 
 }