Make RenderObject::style() return a const object

Source/core/paint/TextPainter.cpp

Index: Source/core/paint/TextPainter.cpp
diff --git a/Source/core/paint/TextPainter.cpp b/Source/core/paint/TextPainter.cpp
index 405b374e57a7d4ca8b75e5c41678cb8e76722488..0d3bab9704e5f226db484a0685cfadd8b95461ec 100644
--- a/Source/core/paint/TextPainter.cpp
+++ b/Source/core/paint/TextPainter.cpp
@@ -108,7 +108,7 @@ static Color textColorForWhiteBackground(Color textColor)
 }
 
 // static
-TextPainter::Style TextPainter::textPaintingStyle(RenderObject& renderer, RenderStyle* style, bool forceBlackText, bool isPrinting)
+TextPainter::Style TextPainter::textPaintingStyle(RenderObject& renderer, const RenderStyle* style, bool forceBlackText, bool isPrinting)
 {
     TextPainter::Style textStyle;
 
@@ -157,7 +157,7 @@ TextPainter::Style TextPainter::selectionPaintingStyle(RenderObject& renderer, b
             selectionStyle.emphasisMarkColor = renderer.selectionEmphasisMarkColor();
         }
 
-        if (RenderStyle* pseudoStyle = renderer.getCachedPseudoStyle(SELECTION)) {
+        if (const RenderStyle* pseudoStyle = renderer.getCachedPseudoStyle(SELECTION)) {
             selectionStyle.strokeColor = forceBlackText ? Color::black : renderer.resolveColor(pseudoStyle, CSSPropertyWebkitTextStrokeColor);
             selectionStyle.strokeWidth = pseudoStyle->textStrokeWidth();
             selectionStyle.shadow = forceBlackText ? 0 : pseudoStyle->textShadow();