Make RenderObject::style() return a const object

Source/core/rendering/RenderDeprecatedFlexibleBox.cpp

 /*
  * This file is part of the render object implementation for KHTML.
  *
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003 Apple Computer, Inc.
  *
  * 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
@@ skipping 158 matching lines @@
 
 static LayoutUnit contentHeightForChild(RenderBox* child)
 {
     if (child->hasOverrideHeight())
         return child->overrideLogicalContentHeight();
     return child->logicalHeight() - child->borderAndPaddingLogicalHeight();
 }
 
 void RenderDeprecatedFlexibleBox::styleWillChange(StyleDifference diff, const LayoutStyle& newStyle)
 {
-    LayoutStyle* oldStyle = style();
+    const LayoutStyle* oldStyle = style();
     if (oldStyle && !oldStyle->lineClamp().isNone() && newStyle.lineClamp().isNone())
         clearLineClamp();
 
     RenderBlock::styleWillChange(diff, newStyle);
 }
 
 void RenderDeprecatedFlexibleBox::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
 {
     if (hasMultipleLines() || isVertical()) {
         for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
@@ skipping 838 matching lines @@
     if (isOutOfFlowPositioned())
         return "RenderDeprecatedFlexibleBox (positioned)";
     if (isAnonymous())
         return "RenderDeprecatedFlexibleBox (generated)";
     if (isRelPositioned())
         return "RenderDeprecatedFlexibleBox (relative positioned)";
     return "RenderDeprecatedFlexibleBox";
 }
 
 } // namespace blink