Make RenderObject::style() return a const object

Source/core/layout/LayoutTheme.cpp

Index: Source/core/layout/LayoutTheme.cpp
diff --git a/Source/core/layout/LayoutTheme.cpp b/Source/core/layout/LayoutTheme.cpp
index 5705d4167a046c771ed54632c8fb85e8bd0c811e..1949705dfcc3cb364bf5b9557ce317fa725a7b99 100644
--- a/Source/core/layout/LayoutTheme.cpp
+++ b/Source/core/layout/LayoutTheme.cpp
@@ -233,7 +233,7 @@ bool LayoutTheme::paint(RenderObject* o, const PaintInfo& paintInfo, const IntRe
 {
     ControlPart part = o->style()->appearance();
 
-    if (shouldUseFallbackTheme(o->style()))
+    if (shouldUseFallbackTheme(o->deprecatedMutableStyle()))
         return paintUsingFallbackTheme(o, paintInfo, r);
 
 #if USE(NEW_THEME)
@@ -839,7 +839,7 @@ void LayoutTheme::paintSliderTicks(RenderObject* o, const PaintInfo& paintInfo,
     IntSize thumbSize;
     RenderObject* thumbRenderer = input->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderThumb())->renderer();
     if (thumbRenderer) {
-        RenderStyle* thumbStyle = thumbRenderer->style();
+        const RenderStyle* thumbStyle = thumbRenderer->style();
         int thumbWidth = thumbStyle->width().intValue();
         int thumbHeight = thumbStyle->height().intValue();
         thumbSize.setWidth(isHorizontal ? thumbWidth : thumbHeight);