Make RenderObject::style() return a const object

Source/core/rendering/svg/RenderSVGResourceMasker.cpp

Index: Source/core/rendering/svg/RenderSVGResourceMasker.cpp
diff --git a/Source/core/rendering/svg/RenderSVGResourceMasker.cpp b/Source/core/rendering/svg/RenderSVGResourceMasker.cpp
index d39ac44b3cc02c866726aab02e08260c7718519b..527b01a558e7414fbdd1df5d280f0287da8d583a 100644
--- a/Source/core/rendering/svg/RenderSVGResourceMasker.cpp
+++ b/Source/core/rendering/svg/RenderSVGResourceMasker.cpp
@@ -134,7 +134,7 @@ void RenderSVGResourceMasker::createPicture(GraphicsContext* context)
         RenderObject* renderer = childElement->renderer();
         if (!renderer)
             continue;
-        RenderStyle* style = renderer->style();
+        const RenderStyle* style = renderer->style();
         if (!style || style->display() == NONE || style->visibility() != VISIBLE)
             continue;
 
@@ -149,7 +149,7 @@ void RenderSVGResourceMasker::calculateMaskContentPaintInvalidationRect()
         RenderObject* renderer = childElement->renderer();
         if (!renderer)
             continue;
-        RenderStyle* style = renderer->style();
+        const RenderStyle* style = renderer->style();
         if (!style || style->display() == NONE || style->visibility() != VISIBLE)
              continue;
         m_maskContentBoundaries.unite(renderer->localToParentTransform().mapRect(renderer->paintInvalidationRectInLocalCoordinates()));