Make RenderObject::style() return a const object

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 315 matching lines @@
 {
     if (m_transform) {
         RenderBox* box = renderBox();
         ASSERT(box);
         m_transform->makeIdentity();
         box->style()->applyTransform(*m_transform, LayoutSize(box->pixelSnappedSize()), RenderStyle::IncludeTransformOrigin);
         makeMatrixRenderable(*m_transform, compositor()->hasAcceleratedCompositing());
     }
 }
 
-void RenderLayer::updateTransform(const RenderStyle* oldStyle, RenderStyle* newStyle)
+void RenderLayer::updateTransform(const RenderStyle* oldStyle, const RenderStyle* newStyle)
 {
     if (oldStyle && newStyle->transformDataEquivalent(*oldStyle))
         return;
 
     // hasTransform() on the renderer is also true when there is transform-style: preserve-3d or perspective set,
     // so check style too.
     bool hasTransform = renderer()->hasTransformRelatedProperty() && newStyle->hasTransform();
     bool had3DTransform = has3DTransform();
 
     bool hadTransform = m_transform;
@@ skipping 539 matching lines @@
     m_needsPositionUpdate = false;
 #endif
     return positionOrOffsetChanged;
 }
 
 TransformationMatrix RenderLayer::perspectiveTransform() const
 {
     if (!renderer()->hasTransformRelatedProperty())
         return TransformationMatrix();
 
-    RenderStyle* style = renderer()->style();
+    const RenderStyle* style = renderer()->style();
     if (!style->hasPerspective())
         return TransformationMatrix();
 
     // Maybe fetch the perspective from the backing?
     const IntRect borderBox = toRenderBox(renderer())->pixelSnappedBorderBoxRect();
     const float boxWidth = borderBox.width();
     const float boxHeight = borderBox.height();
 
     float perspectiveOriginX = floatValueForLength(style->perspectiveOriginX(), boxWidth);
     float perspectiveOriginY = floatValueForLength(style->perspectiveOriginY(), boxHeight);
@@ skipping 10 matching lines @@
 
     return t;
 }
 
 FloatPoint RenderLayer::perspectiveOrigin() const
 {
     if (!renderer()->hasTransformRelatedProperty())
         return FloatPoint();
 
     const LayoutRect borderBox = toRenderBox(renderer())->borderBoxRect();
-    RenderStyle* style = renderer()->style();
+    const RenderStyle* style = renderer()->style();
 
     return FloatPoint(floatValueForLength(style->perspectiveOriginX(), borderBox.width().toFloat()), floatValueForLength(style->perspectiveOriginY(), borderBox.height().toFloat()));
 }
 
 static inline bool isFixedPositionedContainer(RenderLayer* layer)
 {
     return layer->isRootLayer() || layer->hasTransformRelatedProperty();
 }
 
 RenderLayer* RenderLayer::enclosingPositionedAncestor() const
@@ skipping 1988 matching lines @@
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif