Make RenderObject::style() return a const object

Source/core/rendering/RenderFileUploadControl.cpp

 /*
  * Copyright (C) 2006, 2007, 2012 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 97 matching lines @@
     if (!style()->width().isPercent())
         minLogicalWidth = maxLogicalWidth;
 }
 
 void RenderFileUploadControl::computePreferredLogicalWidths()
 {
     ASSERT(preferredLogicalWidthsDirty());
 
     m_minPreferredLogicalWidth = 0;
     m_maxPreferredLogicalWidth = 0;
-    RenderStyle* styleToUse = style();
+    const RenderStyle* styleToUse = style();
 
     if (styleToUse->width().isFixed() && styleToUse->width().value() > 0)
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = adjustContentBoxLogicalWidthForBoxSizing(styleToUse->width().value());
     else
         computeIntrinsicLogicalWidths(m_minPreferredLogicalWidth, m_maxPreferredLogicalWidth);
 
     if (styleToUse->minWidth().isFixed() && styleToUse->minWidth().value() > 0) {
         m_maxPreferredLogicalWidth = std::max(m_maxPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(styleToUse->minWidth().value()));
         m_minPreferredLogicalWidth = std::max(m_minPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(styleToUse->minWidth().value()));
     }
@@ skipping 32 matching lines @@
 }
 
 String RenderFileUploadControl::fileTextValue() const
 {
     HTMLInputElement* input = toHTMLInputElement(node());
     ASSERT(input->files());
     return LayoutTheme::theme().fileListNameForWidth(input->locale(), input->files(), style()->font(), maxFilenameWidth());
 }
 
 } // namespace blink