Constify and use LayoutStyle reference in layout/

Source/core/layout/svg/SVGLayoutTreeAsText.cpp

Index: Source/core/layout/svg/SVGLayoutTreeAsText.cpp
diff --git a/Source/core/layout/svg/SVGLayoutTreeAsText.cpp b/Source/core/layout/svg/SVGLayoutTreeAsText.cpp
index 60731a29839d6c18e9f088a68e62ea39c55176b9..735dfd5bbb0c62de6962ca6b1dfa3d8c39085087 100644
--- a/Source/core/layout/svg/SVGLayoutTreeAsText.cpp
+++ b/Source/core/layout/svg/SVGLayoutTreeAsText.cpp
@@ -270,13 +270,13 @@ static void writeSVGPaintingResource(TextStream& ts, const SVGPaintDescription&
 
 static void writeStyle(TextStream& ts, const LayoutObject& object)
 {
-    const LayoutStyle* style = object.style();
-    const SVGLayoutStyle& svgStyle = style->svgStyle();
+    const LayoutStyle& style = object.styleRef();
+    const SVGLayoutStyle& svgStyle = style.svgStyle();
 
     if (!object.localTransform().isIdentity())
         writeNameValuePair(ts, "transform", object.localTransform());
-    writeIfNotDefault(ts, "image rendering", style->imageRendering(), LayoutStyle::initialImageRendering());
-    writeIfNotDefault(ts, "opacity", style->opacity(), LayoutStyle::initialOpacity());
+    writeIfNotDefault(ts, "image rendering", style.imageRendering(), LayoutStyle::initialImageRendering());
+    writeIfNotDefault(ts, "opacity", style.opacity(), LayoutStyle::initialOpacity());
     if (object.isSVGShape()) {
         const RenderSVGShape& shape = static_cast<const RenderSVGShape&>(object);
         ASSERT(shape.element());
@@ -636,18 +636,15 @@ void writeSVGGradientStop(TextStream& ts, const RenderSVGGradientStop& stop, int
 
     SVGStopElement* stopElement = toSVGStopElement(stop.node());
     ASSERT(stopElement);
-
-    LayoutStyle* style = stop.style();
-    if (!style)
-        return;
+    ASSERT(stop.style());
 
     ts << " [offset=" << stopElement->offset()->currentValue()->value() << "] [color=" << stopElement->stopColorIncludingOpacity() << "]\n";
 }
 
 void writeResources(TextStream& ts, const LayoutObject& object, int indent)
 {
-    const LayoutStyle* style = object.style();
-    const SVGLayoutStyle& svgStyle = style->svgStyle();
+    const LayoutStyle& style = object.styleRef();
+    const SVGLayoutStyle& svgStyle = style.svgStyle();
 
     // FIXME: We want to use SVGResourcesCache to determine which resources are present, instead of quering the resource <-> id cache.
     // For now leave the DRT output as is, but later on we should change this so cycles are properly ignored in the DRT output.