Make RenderObject::style() return a const object

Source/core/svg/SVGElement.cpp

Index: Source/core/svg/SVGElement.cpp
diff --git a/Source/core/svg/SVGElement.cpp b/Source/core/svg/SVGElement.cpp
index 2a831f05a709f94ed976b9a69fcf2121047f27b5..9ce9e60db5e010f709f3ddc73ec12a67d78dbe67 100644
--- a/Source/core/svg/SVGElement.cpp
+++ b/Source/core/svg/SVGElement.cpp
@@ -909,7 +909,7 @@ PassRefPtr<LayoutStyle> SVGElement::customStyleForRenderer()
     if (!correspondingElement())
         return document().ensureStyleResolver().styleForElement(this);
 
-    LayoutStyle* style = 0;
+    const LayoutStyle* style = 0;
     if (Element* parent = parentOrShadowHostElement()) {
         if (LayoutObject* renderer = parent->renderer())
             style = renderer->style();
@@ -941,7 +941,7 @@ LayoutStyle* SVGElement::computedStyle(PseudoId pseudoElementSpecifier)
     if (!hasSVGRareData() || !svgRareData()->useOverrideComputedStyle())
         return Element::computedStyle(pseudoElementSpecifier);
 
-    LayoutStyle* parentStyle = 0;
+    const LayoutStyle* parentStyle = 0;
     if (Element* parent = parentOrShadowHostElement()) {
         if (LayoutObject* renderer = parent->renderer())
             parentStyle = renderer->style();