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 d5fd5d746acaf35d311efa19fd03544851583fe1..beb3b0e00303a19cd44876b8b1a9425c893e7b78 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();
-    LayoutStyle* style = candidate.layoutStyle();
+    const LayoutStyle* style = candidate.layoutStyle();
     if (!style)
         return false;
     if (!style->isSharable())
@@ -344,7 +344,7 @@ LayoutStyle* SharedStyleFinder::findSharedStyle()
         return 0;
     }
 
-    return shareElement->layoutStyle();
+    return shareElement->mutableLayoutStyle();
 }
 
 }