Make RenderObject::style() return a const object

Source/core/css/resolver/SharedStyleFinder.cpp

Index: Source/core/css/resolver/SharedStyleFinder.cpp
diff --git a/Source/core/css/resolver/SharedStyleFinder.cpp b/Source/core/css/resolver/SharedStyleFinder.cpp
index f4c58cc8da9a8dc4e06ae81c955cc29b5882eac4..ccbe5c4db517ab695f72f516bb613982efe6253a 100644
--- a/Source/core/css/resolver/SharedStyleFinder.cpp
+++ b/Source/core/css/resolver/SharedStyleFinder.cpp
@@ -198,7 +198,7 @@ bool SharedStyleFinder::canShareStyleWithElement(Element& candidate) const
     if (element() == candidate)
         return false;
     Element* parent = candidate.parentOrShadowHostElement();
-    RenderStyle* style = candidate.renderStyle();
+    const RenderStyle* style = candidate.renderStyle();
     if (!style)
         return false;
     if (!style->isSharable())
@@ -344,7 +344,7 @@ RenderStyle* SharedStyleFinder::findSharedStyle()
         return 0;
     }
 
-    return shareElement->renderStyle();
+    return shareElement->mutableRenderStyle();
 }
 
 }