Make RenderObject::style() return a const object

Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2602 matching lines @@
         rendererForFirstLineStyle = renderer->parent();
 
     if (rendererForFirstLineStyle->isRenderBlockFlow() || rendererForFirstLineStyle->isRenderButton()) {
         if (RenderBlock* firstLineBlock = rendererForFirstLineStyle->firstLineBlock()) {
             if (type == Cached)
                 return firstLineBlock->getCachedPseudoStyle(FIRST_LINE, style);
             return firstLineBlock->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE), style, firstLineBlock == renderer ? style : 0);
         }
     } else if (!rendererForFirstLineStyle->isAnonymous() && rendererForFirstLineStyle->isRenderInline()
         && !rendererForFirstLineStyle->node()->isFirstLetterPseudoElement()) {
-        LayoutStyle* parentStyle = rendererForFirstLineStyle->parent()->firstLineStyle();
+        const LayoutStyle* 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->mutableStyle()->setHasPseudoStyle(FIRST_LINE_INHERITED);
                 return rendererForFirstLineStyle->getCachedPseudoStyle(FIRST_LINE_INHERITED, parentStyle);
             }
             return rendererForFirstLineStyle->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE_INHERITED), parentStyle, style);
         }
     }
     return nullptr;
 }
 
 PassRefPtr<LayoutStyle> LayoutObject::uncachedFirstLineStyle(LayoutStyle* style) const
 {
     if (!document().styleEngine()->usesFirstLineRules())
         return nullptr;
 
     ASSERT(!isText());
 
     return firstLineStyleForCachedUncachedType(Uncached, this, style);
 }
 
 LayoutStyle* LayoutObject::cachedFirstLineStyle() const
 {
     ASSERT(document().styleEngine()->usesFirstLineRules());
 
     if (RefPtr<LayoutStyle> style = firstLineStyleForCachedUncachedType(Cached, isText() ? parent() : this, m_style.get()))
         return style.get();
 
     return m_style.get();
 }
 
-LayoutStyle* LayoutObject::getCachedPseudoStyle(PseudoId pseudo, LayoutStyle* parentStyle) const
+LayoutStyle* LayoutObject::getCachedPseudoStyle(PseudoId pseudo, const LayoutStyle* parentStyle) const
 {
     if (pseudo < FIRST_INTERNAL_PSEUDOID && !style()->hasPseudoStyle(pseudo))
         return 0;
 
     LayoutStyle* cachedStyle = style()->getCachedPseudoStyle(pseudo);
     if (cachedStyle)
         return cachedStyle;
 
     RefPtr<LayoutStyle> result = getUncachedPseudoStyle(PseudoStyleRequest(pseudo), parentStyle);
     if (result)
-        return style()->addCachedPseudoStyle(result.release());
+        return mutableStyle()->addCachedPseudoStyle(result.release());
     return 0;
 }
 
-PassRefPtr<LayoutStyle> LayoutObject::getUncachedPseudoStyle(const PseudoStyleRequest& pseudoStyleRequest, LayoutStyle* parentStyle, LayoutStyle* ownStyle) const
+PassRefPtr<LayoutStyle> LayoutObject::getUncachedPseudoStyle(const PseudoStyleRequest& pseudoStyleRequest, const LayoutStyle* parentStyle, const LayoutStyle* ownStyle) const
 {
     if (pseudoStyleRequest.pseudoId < FIRST_INTERNAL_PSEUDOID && !ownStyle && !style()->hasPseudoStyle(pseudoStyleRequest.pseudoId))
         return nullptr;
 
     if (!parentStyle) {
         ASSERT(!ownStyle);
         parentStyle = style();
     }
 
     if (!node())
@@ skipping 24 matching lines @@
             }
         }
     }
 
     return getUncachedPseudoStyle(PseudoStyleRequest(SELECTION));
 }
 
 void LayoutObject::getTextDecorations(unsigned decorations, AppliedTextDecoration& underline, AppliedTextDecoration& overline, AppliedTextDecoration& linethrough, bool quirksMode, bool firstlineStyle)
 {
     LayoutObject* curr = this;
-    LayoutStyle* styleToUse = 0;
+    const LayoutStyle* styleToUse = 0;
     unsigned currDecs = TextDecorationNone;
     Color resultColor;
     TextDecorationStyle resultStyle;
     do {
         styleToUse = curr->style(firstlineStyle);
         currDecs = styleToUse->textDecoration();
         currDecs &= decorations;
         resultColor = styleToUse->visitedDependentColor(CSSPropertyTextDecorationColor);
         resultStyle = styleToUse->textDecorationStyle();
         // Parameter 'decorations' is cast as an int to enable the bitwise operations below.
@@ skipping 448 matching lines @@
 {
     if (object1) {
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif