Make RenderObject::style() return a const object

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 04356d0b344fbfe5426e8b81ea019cbf6708687a..9b58992c849e75b8c9bee0808a855ddb292a1235 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -1036,10 +1036,10 @@ bool Node::canStartSelection() const
         return true;
 
     if (renderer()) {
-        LayoutStyle* style = renderer()->style();
+        const LayoutStyle& style = renderer()->styleRef();
         // We allow selections to begin within an element that has -webkit-user-select: none set,
         // but if the element is draggable then dragging should take priority over selection.
-        if (style->userDrag() == DRAG_ELEMENT && style->userSelect() == SELECT_NONE)
+        if (style.userDrag() == DRAG_ELEMENT && style.userSelect() == SELECT_NONE)
             return false;
     }
     return parentOrShadowHostNode() ? parentOrShadowHostNode()->canStartSelection() : true;