Turn styleWillChange |newStyle| into a reference

Source/core/rendering/RenderButton.cpp

 /**
  * Copyright (C) 2005 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
  * 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 45 matching lines @@
     // are not m_inner prevents security problems when that assumption is
     // violated.
     if (oldChild == m_inner || !m_inner || oldChild->parent() == this) {
         ASSERT(oldChild == m_inner || !m_inner);
         RenderFlexibleBox::removeChild(oldChild);
         m_inner = 0;
     } else
         m_inner->removeChild(oldChild);
 }
 
-void RenderButton::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
+void RenderButton::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 {
     if (m_inner) {
         // RenderBlock::setStyle is going to apply a new style to the inner block, which
         // will have the initial flex value, 0. The current value is 1, because we set
         // it right below. Here we change it back to 0 to avoid getting a spurious layout hint
         // because of the difference. Same goes for the other properties.
         // FIXME: Make this hack unnecessary.
-        m_inner->style()->setFlexGrow(newStyle->initialFlexGrow());
-        m_inner->style()->setMarginTop(newStyle->initialMargin());
-        m_inner->style()->setMarginBottom(newStyle->initialMargin());
+        m_inner->style()->setFlexGrow(newStyle.initialFlexGrow());
+        m_inner->style()->setMarginTop(newStyle.initialMargin());
+        m_inner->style()->setMarginBottom(newStyle.initialMargin());
     }
     RenderBlock::styleWillChange(diff, newStyle);
 }
 
 void RenderButton::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     RenderBlock::styleDidChange(diff, oldStyle);
 
     if (m_inner) // RenderBlock handled updating the anonymous block's style.
         setupInnerStyle(m_inner->style());
@@ skipping 38 matching lines @@
         // baseline for the empty case manually here.
         if (direction == HorizontalLine)
             return marginTop() + borderTop() + paddingTop() + contentHeight();
 
         return marginRight() + borderRight() + paddingRight() + contentWidth();
     }
     return RenderFlexibleBox::baselinePosition(baseline, firstLine, direction, linePositionMode);
 }
 
 } // namespace WebCore