Remove unnecessary RenderFlowThread usage and inclusion.

Source/core/rendering/RootInlineBox.cpp

 /*
  * Copyright (C) 2003, 2006, 2008 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 10 matching lines @@
 #include "core/rendering/RootInlineBox.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/StyleEngine.h"
 #include "core/paint/RootInlineBoxPainter.h"
 #include "core/rendering/EllipsisBox.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBlockFlow.h"
-#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/VerticalPositionCache.h"
 #include "platform/text/BidiResolver.h"
 #include "wtf/unicode/Unicode.h"
 
 namespace blink {
 
 struct SameSizeAsRootInlineBox : public InlineFlowBox {
     unsigned unsignedVariable;
@@ skipping 815 matching lines @@
 }
 
 #ifndef NDEBUG
 const char* RootInlineBox::boxName() const
 {
     return "RootInlineBox";
 }
 #endif
 
 } // namespace blink