Make RenderObject::style() return a const object

Source/core/layout/LayoutMedia.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 47 matching lines @@
         return;
 
     bool controlsNeedLayout = controlsRenderer->needsLayout();
     LayoutSize newSize = contentBoxRect().size();
     if (newSize == oldSize && !controlsNeedLayout)
         return;
 
     LayoutState state(*this, locationOffset());
 
     controlsRenderer->setLocation(LayoutPoint(borderLeft(), borderTop()) + LayoutSize(paddingLeft(), paddingTop()));
-    controlsRenderer->style()->setHeight(Length(newSize.height(), Fixed));
-    controlsRenderer->style()->setWidth(Length(newSize.width(), Fixed));
+    controlsRenderer->mutableStyleRef().setHeight(Length(newSize.height(), Fixed));
+    controlsRenderer->mutableStyleRef().setWidth(Length(newSize.width(), Fixed));
     controlsRenderer->forceLayout();
     clearNeedsLayout();
 }
 
 bool LayoutMedia::isChildAllowed(LayoutObject* child, const LayoutStyle&) const
 {
     // The only allowed child is the media controls. The user agent stylesheet
     // (mediaControls.css) has ::-webkit-media-controls { display: flex; }. If
     // author style sets display: inline we would get an inline renderer as a
     // child of replaced content, which is not supposed to be possible. This
     // check can be removed if ::-webkit-media-controls is made internal.
     return child->isFlexibleBox();
 }
 
 void LayoutMedia::paintReplaced(const PaintInfo&, const LayoutPoint&)
 {
 }
 
 } // namespace blink