Make RenderObject::style() return a const object

Source/core/rendering/RenderMenuList.cpp

 /*
  * This file is part of the select element renderer in WebCore.
  *
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *               2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 137 matching lines @@
         m_innerBlock = nullptr;
     } else
         m_innerBlock->removeChild(oldChild);
 }
 
 void RenderMenuList::styleDidChange(StyleDifference diff, const LayoutStyle* oldStyle)
 {
     RenderBlock::styleDidChange(diff, oldStyle);
 
     if (m_buttonText)
-        m_buttonText->setStyle(style());
+        m_buttonText->setStyle(mutableStyle());
     if (m_innerBlock) // RenderBlock handled updating the anonymous block's style.
         adjustInnerStyle();
 
     bool fontChanged = !oldStyle || oldStyle->font() != style()->font();
     if (fontChanged)
         updateOptionsWidth();
 }
 
 void RenderMenuList::updateOptionsWidth()
 {
@@ skipping 68 matching lines @@
                     firstSelectedIndex = i;
             }
         }
 
         if (selectedCount == 1) {
             ASSERT(0 <= firstSelectedIndex);
             ASSERT(firstSelectedIndex < size);
             HTMLOptionElement* selectedOptionElement = toHTMLOptionElement(listItems[firstSelectedIndex]);
             ASSERT(selectedOptionElement->selected());
             text = selectedOptionElement->textIndentedToRespectGroupLabel();
-            m_optionStyle = selectedOptionElement->layoutStyle();
+            m_optionStyle = selectedOptionElement->mutableLayoutStyle();
         } else {
             Locale& locale = select->locale();
             String localizedNumberString = locale.convertToLocalizedNumber(String::number(selectedCount));
             text = locale.queryString(WebLocalizedString::SelectMenuListText, localizedNumberString);
             ASSERT(!m_optionStyle);
         }
     } else {
         const int i = select->optionToListIndex(optionIndex);
         if (i >= 0 && i < size) {
             Element* element = listItems[i];
             if (isHTMLOptionElement(*element)) {
                 text = toHTMLOptionElement(element)->textIndentedToRespectGroupLabel();
-                m_optionStyle = element->layoutStyle();
+                m_optionStyle = element->mutableLayoutStyle();
             }
         }
     }
 
     setText(text.stripWhiteSpace());
 
     didUpdateActiveOption(optionIndex);
 }
 
 void RenderMenuList::setText(const String& s)
 {
     if (s.isEmpty()) {
         if (!m_buttonText || !m_buttonText->isBR()) {
             // FIXME: We should not modify the structure of the render tree
             // during layout. crbug.com/370462
             DeprecatedDisableModifyRenderTreeStructureAsserts disabler;
             if (m_buttonText)
                 m_buttonText->destroy();
             m_buttonText = new LayoutBR(&document());
-            m_buttonText->setStyle(style());
+            m_buttonText->setStyle(mutableStyle());
             addChild(m_buttonText);
         }
     } else {
         if (m_buttonText && !m_buttonText->isBR())
             m_buttonText->setText(s.impl(), true);
         else {
             // FIXME: We should not modify the structure of the render tree
             // during layout. crbug.com/370462
             DeprecatedDisableModifyRenderTreeStructureAsserts disabler;
             if (m_buttonText)
                 m_buttonText->destroy();
             m_buttonText = new RenderText(&document(), s.impl());
-            m_buttonText->setStyle(style());
+            m_buttonText->setStyle(mutableStyle());
             // We need to set the text explicitly though it was specified in the
             // constructor because RenderText doesn't refer to the text
             // specified in the constructor in a case of re-transforming.
             m_buttonText->setText(s.impl(), true);
             addChild(m_buttonText);
         }
         adjustInnerStyle();
     }
 }
 
@@ skipping 79 matching lines @@
     return selectElement()->document().view()->contentsToRootView(pixelSnappedIntRect(absoluteBoundingBoxRect()));
 }
 
 Element& RenderMenuList::ownerElement() const
 {
     return *selectElement();
 }
 
 const LayoutStyle* RenderMenuList::layoutStyleForItem(Element& element) const
 {
-    return element.layoutStyle() ? element.layoutStyle() : element.computedStyle();
+    return element.layoutStyle() ? element.mutableLayoutStyle() : element.computedStyle();
 }
 
 void RenderMenuList::didSetSelectedIndex(int listIndex)
 {
     didUpdateActiveOption(selectElement()->listToOptionIndex(listIndex));
 }
 
 void RenderMenuList::didUpdateActiveOption(int optionIndex)
 {
     if (!document().existingAXObjectCache())
@@ skipping 187 matching lines @@
     HTMLElement* element = listItems[listIndex];
     return isHTMLOptionElement(*element) && toHTMLOptionElement(*element).selected();
 }
 
 void RenderMenuList::setTextFromItem(unsigned listIndex)
 {
     setTextFromOption(selectElement()->listToOptionIndex(listIndex));
 }
 
 } // namespace blink