Make RenderObject::style() return a const object

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index 5ea7e7087c2d8ce6f1b91ddd297541a417cfe425..7468c957bde80b9665ccd2ce38d1f21125419654 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -155,7 +155,7 @@ void RenderObject::operator delete(void* ptr)
 }
 #endif
 
-RenderObject* RenderObject::createObject(Element* element, RenderStyle* style)
+RenderObject* RenderObject::createObject(Element* element, const RenderStyle* style)
 {
     ASSERT(isAllowedToModifyRenderTreeStructure(element->document()));
 
@@ -168,7 +168,7 @@ RenderObject* RenderObject::createObject(Element* element, RenderStyle* style)
         // RenderImageResourceStyleImage requires a style being present on the image but we don't want to
         // trigger a style change now as the node is not fully attached. Moving this code to style change
         // doesn't make sense as it should be run once at renderer creation.
-        image->setStyleInternal(style);
+        image->setStyleInternal(const_cast<RenderStyle*>(style));
         if (const StyleImage* styleImage = toImageContentData(contentData)->image()) {
             image->setImageResource(RenderImageResourceStyleImage::create(const_cast<StyleImage*>(styleImage)));
             image->setIsGeneratedContent();
@@ -1847,7 +1847,7 @@ void RenderObject::propagateStyleToAnonymousChildren(bool blockChildrenOnly)
         if (!document().regionBasedColumnsEnabled()) {
             if (style()->specifiesColumns()) {
                 if (child->style()->specifiesColumns())
-                    newStyle->inheritColumnPropertiesFrom(style());
+                    newStyle->inheritColumnPropertiesFrom(*style());
                 if (child->style()->columnSpan())
                     newStyle->setColumnSpan(ColumnSpanAll);
             }
@@ -2629,11 +2629,11 @@ static PassRefPtr<RenderStyle> firstLineStyleForCachedUncachedType(StyleCacheSta
         }
     } else if (!rendererForFirstLineStyle->isAnonymous() && rendererForFirstLineStyle->isRenderInline()
         && !rendererForFirstLineStyle->node()->isFirstLetterPseudoElement()) {
-        RenderStyle* parentStyle = rendererForFirstLineStyle->parent()->firstLineStyle();
+        const RenderStyle* parentStyle = rendererForFirstLineStyle->parent()->firstLineStyle();
         if (parentStyle != rendererForFirstLineStyle->parent()->style()) {
             if (type == Cached) {
                 // A first-line style is in effect. Cache a first-line style for ourselves.
-                rendererForFirstLineStyle->style()->setHasPseudoStyle(FIRST_LINE_INHERITED);
+                rendererForFirstLineStyle->deprecatedMutableStyle()->setHasPseudoStyle(FIRST_LINE_INHERITED);
                 return rendererForFirstLineStyle->getCachedPseudoStyle(FIRST_LINE_INHERITED, parentStyle);
             }
             return rendererForFirstLineStyle->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE_INHERITED), parentStyle, style);
@@ -2662,7 +2662,7 @@ RenderStyle* RenderObject::cachedFirstLineStyle() const
     return m_style.get();
 }
 
-RenderStyle* RenderObject::getCachedPseudoStyle(PseudoId pseudo, RenderStyle* parentStyle) const
+RenderStyle* RenderObject::getCachedPseudoStyle(PseudoId pseudo, const RenderStyle* parentStyle) const
 {
     if (pseudo < FIRST_INTERNAL_PSEUDOID && !style()->hasPseudoStyle(pseudo))
         return 0;
@@ -2673,11 +2673,11 @@ RenderStyle* RenderObject::getCachedPseudoStyle(PseudoId pseudo, RenderStyle* pa
 
     RefPtr<RenderStyle> result = getUncachedPseudoStyle(PseudoStyleRequest(pseudo), parentStyle);
     if (result)
-        return style()->addCachedPseudoStyle(result.release());
+        return deprecatedMutableStyle()->addCachedPseudoStyle(result.release());
     return 0;
 }
 
-PassRefPtr<RenderStyle> RenderObject::getUncachedPseudoStyle(const PseudoStyleRequest& pseudoStyleRequest, RenderStyle* parentStyle, RenderStyle* ownStyle) const
+PassRefPtr<RenderStyle> RenderObject::getUncachedPseudoStyle(const PseudoStyleRequest& pseudoStyleRequest, const RenderStyle* parentStyle, const RenderStyle* ownStyle) const
 {
     if (pseudoStyleRequest.pseudoId < FIRST_INTERNAL_PSEUDOID && !ownStyle && !style()->hasPseudoStyle(pseudoStyleRequest.pseudoId))
         return nullptr;
@@ -2722,7 +2722,7 @@ PassRefPtr<RenderStyle> RenderObject::getUncachedPseudoStyleFromParentOrShadowHo
 void RenderObject::getTextDecorations(unsigned decorations, AppliedTextDecoration& underline, AppliedTextDecoration& overline, AppliedTextDecoration& linethrough, bool quirksMode, bool firstlineStyle)
 {
     RenderObject* curr = this;
-    RenderStyle* styleToUse = 0;
+    const RenderStyle* styleToUse = 0;
     unsigned currDecs = TextDecorationNone;
     Color resultColor;
     TextDecorationStyle resultStyle;