Remove unnecessary repaint from line layout and cleanup logic

Source/core/rendering/line/LineLayoutState.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2014 Adobe Systems Incorporated. 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.
@@ skipping 24 matching lines @@
 // during an entire linebox tree layout pass (aka layoutInlineChildren).
 class LineLayoutState {
 public:
     LineLayoutState(bool fullLayout, LayoutUnit& repaintLogicalTop, LayoutUnit& repaintLogicalBottom, RenderFlowThread* flowThread)
         : m_lastFloat(0)
         , m_endLine(0)
         , m_floatIndex(0)
         , m_endLineLogicalTop(0)
         , m_endLineMatched(false)
         , m_checkForFloatsFromLastLine(false)
+        , m_hasInlineChild(false)
         , m_isFullLayout(fullLayout)
         , m_repaintLogicalTop(repaintLogicalTop)
         , m_repaintLogicalBottom(repaintLogicalBottom)
         , m_adjustedLogicalLineTop(0)
         , m_usesRepaintBounds(false)
         , m_flowThread(flowThread)
     { }
 
     void markForFullLayout() { m_isFullLayout = true; }
     bool isFullLayout() const { return m_isFullLayout; }
@@ skipping 12 matching lines @@
         m_repaintLogicalTop = std::min(m_repaintLogicalTop, box->logicalTopVisualOverflow() + std::min<LayoutUnit>(paginationDelta, 0));
         m_repaintLogicalBottom = std::max(m_repaintLogicalBottom, box->logicalBottomVisualOverflow() + std::max<LayoutUnit>(paginationDelta, 0));
     }
 
     bool endLineMatched() const { return m_endLineMatched; }
     void setEndLineMatched(bool endLineMatched) { m_endLineMatched = endLineMatched; }
 
     bool checkForFloatsFromLastLine() const { return m_checkForFloatsFromLastLine; }
     void setCheckForFloatsFromLastLine(bool check) { m_checkForFloatsFromLastLine = check; }
 
+    bool hasInlineChild() const { return m_hasInlineChild; }
+    void setHasInlineChild(bool hasInlineChild) { m_hasInlineChild = hasInlineChild; }
+
     LineInfo& lineInfo() { return m_lineInfo; }
     const LineInfo& lineInfo() const { return m_lineInfo; }
 
     LayoutUnit endLineLogicalTop() const { return m_endLineLogicalTop; }
     void setEndLineLogicalTop(LayoutUnit logicalTop) { m_endLineLogicalTop = logicalTop; }
 
     RootInlineBox* endLine() const { return m_endLine; }
     void setEndLine(RootInlineBox* line) { m_endLine = line; }
 
     FloatingObject* lastFloat() const { return m_lastFloat; }
@@ skipping 12 matching lines @@
 
 private:
     Vector<RenderBlockFlow::FloatWithRect> m_floats;
     FloatingObject* m_lastFloat;
     RootInlineBox* m_endLine;
     LineInfo m_lineInfo;
     unsigned m_floatIndex;
     LayoutUnit m_endLineLogicalTop;
     bool m_endLineMatched;
     bool m_checkForFloatsFromLastLine;
+    // Used as a performance optimization to avoid doing a full repaint when our floats
+    // change but we don't have any inline children.
+    bool m_hasInlineChild;
 
     bool m_isFullLayout;
 
     // FIXME: Should this be a range object instead of two ints?
     LayoutUnit& m_repaintLogicalTop;
     LayoutUnit& m_repaintLogicalBottom;
 
     LayoutUnit m_adjustedLogicalLineTop;
 
     bool m_usesRepaintBounds;
 
     RenderFlowThread* m_flowThread;
 };
 
 }
 
 #endif // LineLayoutState_h