Make RenderObject::style() return a const object

Source/core/rendering/RenderBox.h

Index: Source/core/rendering/RenderBox.h
diff --git a/Source/core/rendering/RenderBox.h b/Source/core/rendering/RenderBox.h
index 2d621ea2131b6f4f446f5f69067692853528a044..ae0ffae89163326456f115904c6b9940618f6f3d 100644
--- a/Source/core/rendering/RenderBox.h
+++ b/Source/core/rendering/RenderBox.h
@@ -592,10 +592,10 @@ public:
     LayoutPoint topLeftLocation() const;
     LayoutSize topLeftLocationOffset() const { return toLayoutSize(topLeftLocation()); }
 
-    LayoutRect logicalVisualOverflowRectForPropagation(RenderStyle*) const;
-    LayoutRect visualOverflowRectForPropagation(RenderStyle*) const;
-    LayoutRect logicalLayoutOverflowRectForPropagation(RenderStyle*) const;
-    LayoutRect layoutOverflowRectForPropagation(RenderStyle*) const;
+    LayoutRect logicalVisualOverflowRectForPropagation(const RenderStyle*) const;
+    LayoutRect visualOverflowRectForPropagation(const RenderStyle*) const;
+    LayoutRect logicalLayoutOverflowRectForPropagation(const RenderStyle*) const;
+    LayoutRect layoutOverflowRectForPropagation(const RenderStyle*) const;
 
     bool hasRenderOverflow() const { return m_overflow; }
     bool hasVisualOverflow() const { return m_overflow && !borderBoxRect().contains(m_overflow->visualOverflowRect()); }