CSSValue Immediates: Change CSSValue to an object instead of a pointer

Source/core/editing/EditingStyle.cpp

 /*
  * Copyright (C) 2007, 2008, 2009 Apple Computer, Inc.
  * Copyright (C) 2010, 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 131 matching lines @@
 static PassRefPtrWillBeRawPtr<MutableStylePropertySet> editingStyleFromComputedStyle(PassRefPtrWillBeRawPtr<CSSComputedStyleDeclaration> style, EditingPropertiesType type = OnlyInheritableEditingProperties)
 {
     if (!style)
         return MutableStylePropertySet::create();
     return copyEditingProperties(style.get(), type);
 }
 
 static PassRefPtrWillBeRawPtr<MutableStylePropertySet> getPropertiesNotIn(StylePropertySet* styleWithRedundantProperties, CSSStyleDeclaration* baseStyle);
 enum LegacyFontSizeMode { AlwaysUseLegacyFontSize, UseLegacyFontSizeOnlyIfPixelValuesMatch };
 static int legacyFontSizeFromCSSValue(Document*, CSSPrimitiveValue*, bool, LegacyFontSizeMode);
-static bool isTransparentColorValue(CSSValue*);
+static bool isTransparentColorValue(NullableCSSValue);
 static bool hasTransparentBackgroundColor(CSSStyleDeclaration*);
 static bool hasTransparentBackgroundColor(StylePropertySet*);
-static PassRefPtrWillBeRawPtr<CSSValue> backgroundColorInEffect(Node*);
+static NullableCSSValue backgroundColorInEffect(Node*);
 
 class HTMLElementEquivalent : public NoBaseWillBeGarbageCollected<HTMLElementEquivalent> {
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(HTMLElementEquivalent);
     DECLARE_EMPTY_VIRTUAL_DESTRUCTOR_WILL_BE_REMOVED(HTMLElementEquivalent);
 public:
     static PassOwnPtrWillBeRawPtr<HTMLElementEquivalent> create(CSSPropertyID propertyID, CSSValueID primitiveValue, const HTMLQualifiedName& tagName)
     {
         return adoptPtrWillBeNoop(new HTMLElementEquivalent(propertyID, primitiveValue, tagName));
     }
 
@@ skipping 31 matching lines @@
 HTMLElementEquivalent::HTMLElementEquivalent(CSSPropertyID id, CSSValueID primitiveValue, const HTMLQualifiedName& tagName)
     : m_propertyID(id)
     , m_primitiveValue(CSSPrimitiveValue::createIdentifier(primitiveValue))
     , m_tagName(&tagName)
 {
     ASSERT(primitiveValue != CSSValueInvalid);
 }
 
 bool HTMLElementEquivalent::valueIsPresentInStyle(HTMLElement* element, StylePropertySet* style) const
 {
-    RefPtrWillBeRawPtr<CSSValue> value = style->getPropertyCSSValue(m_propertyID);
-    return matches(element) && value && value->isPrimitiveValue() && toCSSPrimitiveValue(value.get())->getValueID() == m_primitiveValue->getValueID();
+    NullableCSSValue value = style->getPropertyCSSValue(m_propertyID);
+    return matches(element) && value && value->isPrimitiveValue() && toCSSPrimitiveValue(value)->getValueID() == m_primitiveValue->getValueID();
 }
 
 void HTMLElementEquivalent::addToStyle(Element*, EditingStyle* style) const
 {
     style->setProperty(m_propertyID, m_primitiveValue->cssText());
 }
 
 class HTMLTextDecorationEquivalent final : public HTMLElementEquivalent {
 public:
     static PassOwnPtrWillBeRawPtr<HTMLElementEquivalent> create(CSSValueID primitiveValue, const HTMLQualifiedName& tagName)
@@ skipping 16 matching lines @@
 }
 
 bool HTMLTextDecorationEquivalent::propertyExistsInStyle(const StylePropertySet* style) const
 {
     return style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect)
         || style->getPropertyCSSValue(textDecorationPropertyForEditing());
 }
 
 bool HTMLTextDecorationEquivalent::valueIsPresentInStyle(HTMLElement* element, StylePropertySet* style) const
 {
-    RefPtrWillBeRawPtr<CSSValue> styleValue = style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+    NullableCSSValue styleValue = style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
     if (!styleValue)
         styleValue = style->getPropertyCSSValue(textDecorationPropertyForEditing());
-    return matches(element) && styleValue && styleValue->isValueList() && toCSSValueList(styleValue.get())->hasValue(m_primitiveValue.get());
+    return matches(element) && styleValue && styleValue->isValueList() && toCSSValueList(styleValue)->hasValue(CSSValue(*m_primitiveValue.get()));
 }
 
 class HTMLAttributeEquivalent : public HTMLElementEquivalent {
 public:
     static PassOwnPtrWillBeRawPtr<HTMLAttributeEquivalent> create(CSSPropertyID propertyID, const HTMLQualifiedName& tagName, const QualifiedName& attrName)
     {
         return adoptPtrWillBeNoop(new HTMLAttributeEquivalent(propertyID, tagName, attrName));
     }
     static PassOwnPtrWillBeRawPtr<HTMLAttributeEquivalent> create(CSSPropertyID propertyID, const QualifiedName& attrName)
     {
         return adoptPtrWillBeNoop(new HTMLAttributeEquivalent(propertyID, attrName));
     }
 
     virtual bool matches(const Element* element) const override { return HTMLElementEquivalent::matches(element) && element->hasAttribute(m_attrName); }
     virtual bool hasAttribute() const override { return true; }
     virtual bool valueIsPresentInStyle(HTMLElement*, StylePropertySet*) const override;
     virtual void addToStyle(Element*, EditingStyle*) const override;
-    virtual PassRefPtrWillBeRawPtr<CSSValue> attributeValueAsCSSValue(Element*) const;
+    virtual NullableCSSValue attributeValueAsCSSValue(Element*) const;
     inline const QualifiedName& attributeName() const { return m_attrName; }
 
     DEFINE_INLINE_VIRTUAL_TRACE() { HTMLElementEquivalent::trace(visitor); }
 
 protected:
     HTMLAttributeEquivalent(CSSPropertyID, const HTMLQualifiedName& tagName, const QualifiedName& attrName);
     HTMLAttributeEquivalent(CSSPropertyID, const QualifiedName& attrName);
     const QualifiedName& m_attrName; // We can store a reference because HTML attribute names are const global.
 };
 
 HTMLAttributeEquivalent::HTMLAttributeEquivalent(CSSPropertyID id, const HTMLQualifiedName& tagName, const QualifiedName& attrName)
     : HTMLElementEquivalent(id, tagName)
     , m_attrName(attrName)
 {
 }
 
 HTMLAttributeEquivalent::HTMLAttributeEquivalent(CSSPropertyID id, const QualifiedName& attrName)
     : HTMLElementEquivalent(id)
     , m_attrName(attrName)
 {
 }
 
 bool HTMLAttributeEquivalent::valueIsPresentInStyle(HTMLElement* element, StylePropertySet* style) const
 {
-    RefPtrWillBeRawPtr<CSSValue> value = attributeValueAsCSSValue(element);
-    RefPtrWillBeRawPtr<CSSValue> styleValue = style->getPropertyCSSValue(m_propertyID);
+    NullableCSSValue value = attributeValueAsCSSValue(element);
+    NullableCSSValue styleValue = style->getPropertyCSSValue(m_propertyID);
 
-    return compareCSSValuePtr(value, styleValue);
+    return value == styleValue;
 }
 
 void HTMLAttributeEquivalent::addToStyle(Element* element, EditingStyle* style) const
 {
-    if (RefPtrWillBeRawPtr<CSSValue> value = attributeValueAsCSSValue(element))
+    if (NullableCSSValue value = attributeValueAsCSSValue(element))
         style->setProperty(m_propertyID, value->cssText());
 }
 
-PassRefPtrWillBeRawPtr<CSSValue> HTMLAttributeEquivalent::attributeValueAsCSSValue(Element* element) const
+NullableCSSValue HTMLAttributeEquivalent::attributeValueAsCSSValue(Element* element) const
 {
     ASSERT(element);
     const AtomicString& value = element->getAttribute(m_attrName);
     if (value.isNull())
         return nullptr;
 
     RefPtrWillBeRawPtr<MutableStylePropertySet> dummyStyle = nullptr;
     dummyStyle = MutableStylePropertySet::create();
     dummyStyle->setProperty(m_propertyID, value);
     return dummyStyle->getPropertyCSSValue(m_propertyID);
 }
 
 class HTMLFontSizeEquivalent final : public HTMLAttributeEquivalent {
 public:
     static PassOwnPtrWillBeRawPtr<HTMLFontSizeEquivalent> create()
     {
         return adoptPtrWillBeNoop(new HTMLFontSizeEquivalent());
     }
-    virtual PassRefPtrWillBeRawPtr<CSSValue> attributeValueAsCSSValue(Element*) const override;
+    virtual NullableCSSValue attributeValueAsCSSValue(Element*) const override;
 
     DEFINE_INLINE_VIRTUAL_TRACE() { HTMLAttributeEquivalent::trace(visitor); }
 
 private:
     HTMLFontSizeEquivalent();
 };
 
 HTMLFontSizeEquivalent::HTMLFontSizeEquivalent()
     : HTMLAttributeEquivalent(CSSPropertyFontSize, HTMLNames::fontTag, HTMLNames::sizeAttr)
 {
 }
 
-PassRefPtrWillBeRawPtr<CSSValue> HTMLFontSizeEquivalent::attributeValueAsCSSValue(Element* element) const
+NullableCSSValue HTMLFontSizeEquivalent::attributeValueAsCSSValue(Element* element) const
 {
     ASSERT(element);
     const AtomicString& value = element->getAttribute(m_attrName);
     if (value.isNull())
         return nullptr;
     CSSValueID size;
     if (!HTMLFontElement::cssValueFromFontSizeNumber(value, size))
         return nullptr;
     return CSSPrimitiveValue::createIdentifier(size);
 }
@@ skipping 33 matching lines @@
     , m_isMonospaceFont(false)
     , m_fontSizeDelta(NoFontDelta)
 {
     setProperty(propertyID, value);
 }
 
 EditingStyle::~EditingStyle()
 {
 }
 
-static RGBA32 cssValueToRGBA(CSSValue* colorValue)
+static RGBA32 cssValueToRGBA(NullableCSSValue colorValue)
 {
     if (!colorValue || !colorValue->isPrimitiveValue())
         return Color::transparent;
 
     CSSPrimitiveValue* primitiveColor = toCSSPrimitiveValue(colorValue);
     if (primitiveColor->isRGBColor())
         return primitiveColor->getRGBA32Value();
 
     RGBA32 rgba = 0;
     // FIXME: Why ignore the return value?
     CSSParser::parseColor(rgba, colorValue->cssText());
     return rgba;
 }
 
 static inline RGBA32 getRGBAFontColor(CSSStyleDeclaration* style)
 {
-    return cssValueToRGBA(style->getPropertyCSSValueInternal(CSSPropertyColor).get());
+    return cssValueToRGBA(style->getPropertyCSSValueInternal(CSSPropertyColor));
 }
 
 static inline RGBA32 getRGBAFontColor(StylePropertySet* style)
 {
-    return cssValueToRGBA(style->getPropertyCSSValue(CSSPropertyColor).get());
+    return cssValueToRGBA(style->getPropertyCSSValue(CSSPropertyColor));
 }
 
 static inline RGBA32 getRGBABackgroundColor(CSSStyleDeclaration* style)
 {
-    return cssValueToRGBA(style->getPropertyCSSValueInternal(CSSPropertyBackgroundColor).get());
+    return cssValueToRGBA(style->getPropertyCSSValueInternal(CSSPropertyBackgroundColor));
 }
 
 static inline RGBA32 getRGBABackgroundColor(StylePropertySet* style)
 {
-    return cssValueToRGBA(style->getPropertyCSSValue(CSSPropertyBackgroundColor).get());
+    return cssValueToRGBA(style->getPropertyCSSValue(CSSPropertyBackgroundColor));
 }
 
 static inline RGBA32 rgbaBackgroundColorInEffect(Node* node)
 {
-    return cssValueToRGBA(backgroundColorInEffect(node).get());
+    return cssValueToRGBA(backgroundColorInEffect(node));
 }
 
 static int textAlignResolvingStartAndEnd(int textAlign, int direction)
 {
     switch (textAlign) {
     case CSSValueCenter:
     case CSSValueWebkitCenter:
         return CSSValueCenter;
     case CSSValueJustify:
         return CSSValueJustify;
@@ skipping 21 matching lines @@
 {
     if (isTabHTMLSpanElementTextNode(node))
         node = tabSpanElement(node)->parentNode();
     else if (isTabHTMLSpanElement(node))
         node = node->parentNode();
 
     RefPtrWillBeRawPtr<CSSComputedStyleDeclaration> computedStyleAtPosition = CSSComputedStyleDeclaration::create(node);
     m_mutableStyle = propertiesToInclude == AllProperties && computedStyleAtPosition ? computedStyleAtPosition->copyProperties() : editingStyleFromComputedStyle(computedStyleAtPosition);
 
     if (propertiesToInclude == EditingPropertiesInEffect) {
-        if (RefPtrWillBeRawPtr<CSSValue> value = backgroundColorInEffect(node))
+        if (NullableCSSValue value = backgroundColorInEffect(node))
             m_mutableStyle->setProperty(CSSPropertyBackgroundColor, value->cssText());
-        if (RefPtrWillBeRawPtr<CSSValue> value = computedStyleAtPosition->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect))
+        if (NullableCSSValue value = computedStyleAtPosition->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect))
             m_mutableStyle->setProperty(CSSPropertyTextDecoration, value->cssText());
     }
 
     if (node && node->ensureComputedStyle()) {
         const ComputedStyle* computedStyle = node->ensureComputedStyle();
         removeTextFillAndStrokeColorsIfNeeded(computedStyle);
         replaceFontSizeByKeywordIfPossible(computedStyle, computedStyleAtPosition.get());
     }
 
     m_isMonospaceFont = computedStyleAtPosition->isMonospaceFont();
@@ skipping 31 matching lines @@
     if (!m_mutableStyle)
         return;
 
     if (m_mutableStyle->getPropertyCSSValue(CSSPropertyFontSize)) {
         // Explicit font size overrides any delta.
         m_mutableStyle->removeProperty(CSSPropertyWebkitFontSizeDelta);
         return;
     }
 
     // Get the adjustment amount out of the style.
-    RefPtrWillBeRawPtr<CSSValue> value = m_mutableStyle->getPropertyCSSValue(CSSPropertyWebkitFontSizeDelta);
+    NullableCSSValue value = m_mutableStyle->getPropertyCSSValue(CSSPropertyWebkitFontSizeDelta);
     if (!value || !value->isPrimitiveValue())
         return;
 
-    CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value.get());
+    CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
 
     // Only PX handled now. If we handle more types in the future, perhaps
     // a switch statement here would be more appropriate.
     if (!primitiveValue->isPx())
         return;
 
     m_fontSizeDelta = primitiveValue->getFloatValue();
     m_mutableStyle->removeProperty(CSSPropertyWebkitFontSizeDelta);
 }
 
 bool EditingStyle::isEmpty() const
 {
     return (!m_mutableStyle || m_mutableStyle->isEmpty()) && m_fontSizeDelta == NoFontDelta;
 }
 
 bool EditingStyle::textDirection(WritingDirection& writingDirection) const
 {
     if (!m_mutableStyle)
         return false;
 
-    RefPtrWillBeRawPtr<CSSValue> unicodeBidi = m_mutableStyle->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+    NullableCSSValue unicodeBidi = m_mutableStyle->getPropertyCSSValue(CSSPropertyUnicodeBidi);
     if (!unicodeBidi || !unicodeBidi->isPrimitiveValue())
         return false;
 
-    CSSValueID unicodeBidiValue = toCSSPrimitiveValue(unicodeBidi.get())->getValueID();
+    CSSValueID unicodeBidiValue = toCSSPrimitiveValue(unicodeBidi)->getValueID();
     if (unicodeBidiValue == CSSValueEmbed) {
-        RefPtrWillBeRawPtr<CSSValue> direction = m_mutableStyle->getPropertyCSSValue(CSSPropertyDirection);
+        NullableCSSValue direction = m_mutableStyle->getPropertyCSSValue(CSSPropertyDirection);
         if (!direction || !direction->isPrimitiveValue())
             return false;
 
-        writingDirection = toCSSPrimitiveValue(direction.get())->getValueID() == CSSValueLtr ? LeftToRightWritingDirection : RightToLeftWritingDirection;
+        writingDirection = toCSSPrimitiveValue(direction)->getValueID() == CSSValueLtr ? LeftToRightWritingDirection : RightToLeftWritingDirection;
 
         return true;
     }
 
     if (unicodeBidiValue == CSSValueNormal) {
         writingDirection = NaturalWritingDirection;
         return true;
     }
 
     return false;
@@ skipping 82 matching lines @@
     unsigned propertyCount = nodeStyle->propertyCount();
     for (unsigned i = 0; i < propertyCount; ++i)
         m_mutableStyle->removeProperty(nodeStyle->propertyAt(i).id());
 }
 
 void EditingStyle::collapseTextDecorationProperties()
 {
     if (!m_mutableStyle)
         return;
 
-    RefPtrWillBeRawPtr<CSSValue> textDecorationsInEffect = m_mutableStyle->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+    NullableCSSValue textDecorationsInEffect = m_mutableStyle->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
     if (!textDecorationsInEffect)
         return;
 
     if (textDecorationsInEffect->isValueList())
         m_mutableStyle->setProperty(textDecorationPropertyForEditing(), textDecorationsInEffect->cssText(), m_mutableStyle->propertyIsImportant(textDecorationPropertyForEditing()));
     else
         m_mutableStyle->removeProperty(textDecorationPropertyForEditing());
     m_mutableStyle->removeProperty(CSSPropertyWebkitTextDecorationsInEffect);
 }
 
@@ skipping 276 matching lines @@
 {
     if (!m_mutableStyle)
         return;
 
     // ReplaceSelectionCommand::handleStyleSpans() requires that this function only removes the editing style.
     // If this function was modified in the future to delete all redundant properties, then add a boolean value to indicate
     // which one of editingStyleAtPosition or computedStyle is called.
     RefPtrWillBeRawPtr<EditingStyle> editingStyleAtPosition = EditingStyle::create(position, EditingPropertiesInEffect);
     StylePropertySet* styleAtPosition = editingStyleAtPosition->m_mutableStyle.get();
 
-    RefPtrWillBeRawPtr<CSSValue> unicodeBidi = nullptr;
-    RefPtrWillBeRawPtr<CSSValue> direction = nullptr;
+    NullableCSSValue unicodeBidi;
+    NullableCSSValue direction;
     if (shouldPreserveWritingDirection == PreserveWritingDirection) {
         unicodeBidi = m_mutableStyle->getPropertyCSSValue(CSSPropertyUnicodeBidi);
         direction = m_mutableStyle->getPropertyCSSValue(CSSPropertyDirection);
     }
 
     m_mutableStyle->removeEquivalentProperties(styleAtPosition);
 
     if (textAlignResolvingStartAndEnd(m_mutableStyle.get()) == textAlignResolvingStartAndEnd(styleAtPosition))
         m_mutableStyle->removeProperty(CSSPropertyTextAlign);
 
     if (getRGBAFontColor(m_mutableStyle.get()) == getRGBAFontColor(styleAtPosition))
         m_mutableStyle->removeProperty(CSSPropertyColor);
 
     if (hasTransparentBackgroundColor(m_mutableStyle.get())
-        || cssValueToRGBA(m_mutableStyle->getPropertyCSSValue(CSSPropertyBackgroundColor).get()) == rgbaBackgroundColorInEffect(position.containerNode()))
+        || cssValueToRGBA(m_mutableStyle->getPropertyCSSValue(CSSPropertyBackgroundColor)) == rgbaBackgroundColorInEffect(position.containerNode()))
         m_mutableStyle->removeProperty(CSSPropertyBackgroundColor);
 
     if (unicodeBidi && unicodeBidi->isPrimitiveValue()) {
-        m_mutableStyle->setProperty(CSSPropertyUnicodeBidi, toCSSPrimitiveValue(unicodeBidi.get())->getValueID());
+        m_mutableStyle->setProperty(CSSPropertyUnicodeBidi, toCSSPrimitiveValue(unicodeBidi)->getValueID());
         if (direction && direction->isPrimitiveValue())
-            m_mutableStyle->setProperty(CSSPropertyDirection, toCSSPrimitiveValue(direction.get())->getValueID());
+            m_mutableStyle->setProperty(CSSPropertyDirection, toCSSPrimitiveValue(direction)->getValueID());
     }
 }
 
 void EditingStyle::mergeTypingStyle(Document* document)
 {
     ASSERT(document);
 
     RefPtrWillBeRawPtr<EditingStyle> typingStyle = document->frame()->selection().typingStyle();
     if (!typingStyle || typingStyle == this)
         return;
@@ skipping 94 matching lines @@
         if (node->isStyledElement() && !isMailHTMLBlockquoteElement(node)) {
             wrappingStyle->mergeInlineAndImplicitStyleOfElement(toElement(node), EditingStyle::DoNotOverrideValues,
                 EditingStyle::EditingPropertiesInEffect);
         }
     }
 
     return wrappingStyle.release();
 }
 
 
-static void mergeTextDecorationValues(CSSValueList* mergedValue, const CSSValueList* valueToMerge)
+static void mergeTextDecorationValues(CSSValueList& mergedValue, const CSSValueList& valueToMerge)
 {
-    DEFINE_STATIC_REF_WILL_BE_PERSISTENT(CSSPrimitiveValue, underline, (CSSPrimitiveValue::createIdentifier(CSSValueUnderline)));
-    DEFINE_STATIC_REF_WILL_BE_PERSISTENT(CSSPrimitiveValue, lineThrough, (CSSPrimitiveValue::createIdentifier(CSSValueLineThrough)));
-    if (valueToMerge->hasValue(underline) && !mergedValue->hasValue(underline))
-        mergedValue->append(underline);
+    const CSSValue& underline = CSSPrimitiveValue::createIdentifier(CSSValueUnderline);
+    const CSSValue& lineThrough = CSSPrimitiveValue::createIdentifier(CSSValueLineThrough);
 
-    if (valueToMerge->hasValue(lineThrough) && !mergedValue->hasValue(lineThrough))
-        mergedValue->append(lineThrough);
+    if (valueToMerge.hasValue(underline) && !mergedValue.hasValue(underline))
+        mergedValue.append(underline);
+
+    if (valueToMerge.hasValue(lineThrough) && !mergedValue.hasValue(lineThrough))
+        mergedValue.append(lineThrough);
 }
 
 void EditingStyle::mergeStyle(const StylePropertySet* style, CSSPropertyOverrideMode mode)
 {
     if (!style)
         return;
 
     if (!m_mutableStyle) {
         m_mutableStyle = style->mutableCopy();
         return;
     }
 
     unsigned propertyCount = style->propertyCount();
     for (unsigned i = 0; i < propertyCount; ++i) {
         StylePropertySet::PropertyReference property = style->propertyAt(i);
-        RefPtrWillBeRawPtr<CSSValue> value = m_mutableStyle->getPropertyCSSValue(property.id());
+        NullableCSSValue value = m_mutableStyle->getPropertyCSSValue(property.id());
 
         // text decorations never override values
-        if ((property.id() == textDecorationPropertyForEditing() || property.id() == CSSPropertyWebkitTextDecorationsInEffect) && property.value()->isValueList() && value) {
-            if (value->isValueList()) {
-                mergeTextDecorationValues(toCSSValueList(value.get()), toCSSValueList(property.value()));
+        if ((property.id() == textDecorationPropertyForEditing() || property.id() == CSSPropertyWebkitTextDecorationsInEffect) && property.value().isValueList() && value) {
+            if (value && value->isValueList()) {
+                mergeTextDecorationValues(*toCSSValueList(value), toCSSValueList(property.value()));
                 continue;
             }
             value = nullptr; // text-decoration: none is equivalent to not having the property
         }
 
         if (mode == OverrideValues || (mode == DoNotOverrideValues && !value))
-            m_mutableStyle->setProperty(property.id(), property.value()->cssText(), property.isImportant());
+            m_mutableStyle->setProperty(property.id(), property.value().cssText(), property.isImportant());
     }
 }
 
 static PassRefPtrWillBeRawPtr<MutableStylePropertySet> styleFromMatchedRulesForElement(Element* element, unsigned rulesToInclude)
 {
     RefPtrWillBeRawPtr<MutableStylePropertySet> style = MutableStylePropertySet::create();
     RefPtrWillBeRawPtr<StyleRuleList> matchedRules = element->document().ensureStyleResolver().styleRulesForElement(element, rulesToInclude);
     if (matchedRules) {
         for (unsigned i = 0; i < matchedRules->m_list.size(); ++i)
             style->mergeAndOverrideOnConflict(&matchedRules->m_list[i]->properties());
@@ skipping 20 matching lines @@
 
     // The property value, if it's a percentage, may not reflect the actual computed value.
     // For example: style="height: 1%; overflow: visible;" in quirksmode
     // FIXME: There are others like this, see <rdar://problem/5195123> Slashdot copy/paste fidelity problem
     RefPtrWillBeRawPtr<CSSComputedStyleDeclaration> computedStyleForElement = CSSComputedStyleDeclaration::create(element);
     RefPtrWillBeRawPtr<MutableStylePropertySet> fromComputedStyle = MutableStylePropertySet::create();
     {
         unsigned propertyCount = m_mutableStyle->propertyCount();
         for (unsigned i = 0; i < propertyCount; ++i) {
             StylePropertySet::PropertyReference property = m_mutableStyle->propertyAt(i);
-            CSSValue* value = property.value();
-            if (!value->isPrimitiveValue())
+            CSSValue value = property.value();
+            if (!value.isPrimitiveValue())
                 continue;
-            if (toCSSPrimitiveValue(value)->isPercentage()) {
-                if (RefPtrWillBeRawPtr<CSSValue> computedPropertyValue = computedStyleForElement->getPropertyCSSValue(property.id()))
-                    fromComputedStyle->addRespectingCascade(CSSProperty(property.id(), computedPropertyValue));
+            if (toCSSPrimitiveValue(value).isPercentage()) {
+                if (NullableCSSValue computedPropertyValue = computedStyleForElement->getPropertyCSSValue(property.id()))
+                    fromComputedStyle->addRespectingCascade(CSSProperty(property.id(), *computedPropertyValue));
             }
         }
     }
     m_mutableStyle->mergeAndOverrideOnConflict(fromComputedStyle.get());
 }
 
 static void removePropertiesInStyle(MutableStylePropertySet* styleToRemovePropertiesFrom, StylePropertySet* style)
 {
     unsigned propertyCount = style->propertyCount();
     Vector<CSSPropertyID> propertiesToRemove(propertyCount);
@@ skipping 72 matching lines @@
 void EditingStyle::forceInline()
 {
     if (!m_mutableStyle)
         m_mutableStyle = MutableStylePropertySet::create();
     const bool propertyIsImportant = true;
     m_mutableStyle->setProperty(CSSPropertyDisplay, CSSValueInline, propertyIsImportant);
 }
 
 int EditingStyle::legacyFontSize(Document* document) const
 {
-    RefPtrWillBeRawPtr<CSSValue> cssValue = m_mutableStyle->getPropertyCSSValue(CSSPropertyFontSize);
+    NullableCSSValue cssValue = m_mutableStyle->getPropertyCSSValue(CSSPropertyFontSize);
     if (!cssValue || !cssValue->isPrimitiveValue())
         return 0;
-    return legacyFontSizeFromCSSValue(document, toCSSPrimitiveValue(cssValue.get()),
+    return legacyFontSizeFromCSSValue(document, toCSSPrimitiveValue(cssValue),
         m_isMonospaceFont, AlwaysUseLegacyFontSize);
 }
 
 PassRefPtrWillBeRawPtr<EditingStyle> EditingStyle::styleAtSelectionStart(const VisibleSelection& selection, bool shouldUseBackgroundColorInEffect)
 {
     if (selection.isNone())
         return nullptr;
 
     Position position = adjustedSelectionStartForStyleComputation(selection);
 
@@ skipping 10 matching lines @@
         return nullptr;
 
     RefPtrWillBeRawPtr<EditingStyle> style = EditingStyle::create(element, EditingStyle::AllProperties);
     style->mergeTypingStyle(&element->document());
 
     // If background color is transparent, traverse parent nodes until we hit a different value or document root
     // Also, if the selection is a range, ignore the background color at the start of selection,
     // and find the background color of the common ancestor.
     if (shouldUseBackgroundColorInEffect && (selection.isRange() || hasTransparentBackgroundColor(style->m_mutableStyle.get()))) {
         RefPtrWillBeRawPtr<Range> range(selection.toNormalizedRange());
-        if (PassRefPtrWillBeRawPtr<CSSValue> value = backgroundColorInEffect(range->commonAncestorContainer()))
+        if (NullableCSSValue value = backgroundColorInEffect(range->commonAncestorContainer()))
             style->setProperty(CSSPropertyBackgroundColor, value->cssText());
     }
 
     return style;
 }
 
 WritingDirection EditingStyle::textDirectionForSelection(const VisibleSelection& selection, EditingStyle* typingStyle, bool& hasNestedOrMultipleEmbeddings)
 {
     hasNestedOrMultipleEmbeddings = true;
 
@@ skipping 10 matching lines @@
     if (selection.isRange()) {
         end = selection.end().upstream();
 
         ASSERT(end.document());
         Node* pastLast = Range::create(*end.document(), position.parentAnchoredEquivalent(), end.parentAnchoredEquivalent())->pastLastNode();
         for (Node* n = node; n && n != pastLast; n = NodeTraversal::next(*n)) {
             if (!n->isStyledElement())
                 continue;
 
             RefPtrWillBeRawPtr<CSSComputedStyleDeclaration> style = CSSComputedStyleDeclaration::create(n);
-            RefPtrWillBeRawPtr<CSSValue> unicodeBidi = style->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+            NullableCSSValue unicodeBidi = style->getPropertyCSSValue(CSSPropertyUnicodeBidi);
             if (!unicodeBidi || !unicodeBidi->isPrimitiveValue())
                 continue;
 
-            CSSValueID unicodeBidiValue = toCSSPrimitiveValue(unicodeBidi.get())->getValueID();
+            CSSValueID unicodeBidiValue = toCSSPrimitiveValue(unicodeBidi)->getValueID();
             if (unicodeBidiValue == CSSValueEmbed || unicodeBidiValue == CSSValueBidiOverride)
                 return NaturalWritingDirection;
         }
     }
 
     if (selection.isCaret()) {
         WritingDirection direction;
         if (typingStyle && typingStyle->textDirection(direction)) {
             hasNestedOrMultipleEmbeddings = false;
             return direction;
         }
         node = selection.visibleStart().deepEquivalent().deprecatedNode();
     }
 
     // The selection is either a caret with no typing attributes or a range in which no embedding is added, so just use the start position
     // to decide.
     Node* block = enclosingBlock(node);
     WritingDirection foundDirection = NaturalWritingDirection;
 
     for (; node != block; node = node->parentNode()) {
         if (!node->isStyledElement())
             continue;
 
         Element* element = toElement(node);
         RefPtrWillBeRawPtr<CSSComputedStyleDeclaration> style = CSSComputedStyleDeclaration::create(element);
-        RefPtrWillBeRawPtr<CSSValue> unicodeBidi = style->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+        NullableCSSValue unicodeBidi = style->getPropertyCSSValue(CSSPropertyUnicodeBidi);
         if (!unicodeBidi || !unicodeBidi->isPrimitiveValue())
             continue;
 
-        CSSValueID unicodeBidiValue = toCSSPrimitiveValue(unicodeBidi.get())->getValueID();
+        CSSValueID unicodeBidiValue = toCSSPrimitiveValue(unicodeBidi)->getValueID();
         if (unicodeBidiValue == CSSValueNormal)
             continue;
 
         if (unicodeBidiValue == CSSValueBidiOverride)
             return NaturalWritingDirection;
 
         ASSERT(unicodeBidiValue == CSSValueEmbed);
-        RefPtrWillBeRawPtr<CSSValue> direction = style->getPropertyCSSValue(CSSPropertyDirection);
+        NullableCSSValue direction = style->getPropertyCSSValue(CSSPropertyDirection);
         if (!direction || !direction->isPrimitiveValue())
             continue;
 
-        int directionValue = toCSSPrimitiveValue(direction.get())->getValueID();
+        int directionValue = toCSSPrimitiveValue(direction)->getValueID();
         if (directionValue != CSSValueLtr && directionValue != CSSValueRtl)
             continue;
 
         if (foundDirection != NaturalWritingDirection)
             return NaturalWritingDirection;
 
         // In the range case, make sure that the embedding element persists until the end of the range.
         if (selection.isRange() && !end.deprecatedNode()->isDescendantOf(element))
             return NaturalWritingDirection;
 
         foundDirection = directionValue == CSSValueLtr ? LeftToRightWritingDirection : RightToLeftWritingDirection;
     }
     hasNestedOrMultipleEmbeddings = false;
     return foundDirection;
 }
 
 DEFINE_TRACE(EditingStyle)
 {
     visitor->trace(m_mutableStyle);
 }
 
 static void reconcileTextDecorationProperties(MutableStylePropertySet* style)
 {
-    RefPtrWillBeRawPtr<CSSValue> textDecorationsInEffect = style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
-    RefPtrWillBeRawPtr<CSSValue> textDecoration = style->getPropertyCSSValue(textDecorationPropertyForEditing());
+    NullableCSSValue textDecorationsInEffect = style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+    NullableCSSValue textDecoration = style->getPropertyCSSValue(textDecorationPropertyForEditing());
     // We shouldn't have both text-decoration and -webkit-text-decorations-in-effect because that wouldn't make sense.
     ASSERT(!textDecorationsInEffect || !textDecoration);
     if (textDecorationsInEffect) {
         style->setProperty(textDecorationPropertyForEditing(), textDecorationsInEffect->cssText());
         style->removeProperty(CSSPropertyWebkitTextDecorationsInEffect);
         textDecoration = textDecorationsInEffect;
     }
 
     // If text-decoration is set to "none", remove the property because we don't want to add redundant "text-decoration: none".
     if (textDecoration && !textDecoration->isValueList())
@@ skipping 54 matching lines @@
     }
 
     int fontStyle = getIdentifierValue(style, CSSPropertyFontStyle);
     if (fontStyle == CSSValueItalic || fontStyle == CSSValueOblique) {
         style->removeProperty(CSSPropertyFontStyle);
         m_applyItalic = true;
     }
 
     // Assuming reconcileTextDecorationProperties has been called, there should not be -webkit-text-decorations-in-effect
     // Furthermore, text-decoration: none has been trimmed so that text-decoration property is always a CSSValueList.
-    RefPtrWillBeRawPtr<CSSValue> textDecoration = style->getPropertyCSSValue(textDecorationPropertyForEditing());
+    NullableCSSValue textDecoration = style->getPropertyCSSValue(textDecorationPropertyForEditing());
     if (textDecoration && textDecoration->isValueList()) {
         DEFINE_STATIC_REF_WILL_BE_PERSISTENT(CSSPrimitiveValue, underline, (CSSPrimitiveValue::createIdentifier(CSSValueUnderline)));
         DEFINE_STATIC_REF_WILL_BE_PERSISTENT(CSSPrimitiveValue, lineThrough, (CSSPrimitiveValue::createIdentifier(CSSValueLineThrough)));
-        RefPtrWillBeRawPtr<CSSValueList> newTextDecoration = toCSSValueList(textDecoration.get())->copy();
-        if (newTextDecoration->removeAll(underline))
+        RefPtrWillBeRawPtr<CSSValueList> newTextDecoration = toCSSValueList(textDecoration)->copy();
+        if (newTextDecoration->removeAll(CSSValue(*underline)))
             m_applyUnderline = true;
-        if (newTextDecoration->removeAll(lineThrough))
+        if (newTextDecoration->removeAll(CSSValue(*lineThrough)))
             m_applyLineThrough = true;
 
         // If trimTextDecorations, delete underline and line-through
         setTextDecorationProperty(style, newTextDecoration.get(), textDecorationPropertyForEditing());
     }
 
     int verticalAlign = getIdentifierValue(style, CSSPropertyVerticalAlign);
     switch (verticalAlign) {
     case CSSValueSub:
         style->removeProperty(CSSPropertyVerticalAlign);
         m_applySubscript = true;
         break;
     case CSSValueSuper:
         style->removeProperty(CSSPropertyVerticalAlign);
         m_applySuperscript = true;
         break;
     }
 
     if (style->getPropertyCSSValue(CSSPropertyColor)) {
         m_applyFontColor = Color(getRGBAFontColor(style)).serialized();
         style->removeProperty(CSSPropertyColor);
     }
 
     m_applyFontFace = style->getPropertyValue(CSSPropertyFontFamily);
     // Remove single quotes for Outlook 2007 compatibility. See https://bugs.webkit.org/show_bug.cgi?id=79448
     m_applyFontFace.replaceWithLiteral('\'', "");
     style->removeProperty(CSSPropertyFontFamily);
 
-    if (RefPtrWillBeRawPtr<CSSValue> fontSize = style->getPropertyCSSValue(CSSPropertyFontSize)) {
+    if (NullableCSSValue fontSize = style->getPropertyCSSValue(CSSPropertyFontSize)) {
         if (!fontSize->isPrimitiveValue()) {
             style->removeProperty(CSSPropertyFontSize); // Can't make sense of the number. Put no font size.
-        } else if (int legacyFontSize = legacyFontSizeFromCSSValue(document, toCSSPrimitiveValue(fontSize.get()), isMonospaceFont, UseLegacyFontSizeOnlyIfPixelValuesMatch)) {
+        } else if (int legacyFontSize = legacyFontSizeFromCSSValue(document, toCSSPrimitiveValue(fontSize), isMonospaceFont, UseLegacyFontSizeOnlyIfPixelValuesMatch)) {
             m_applyFontSize = String::number(legacyFontSize);
             style->removeProperty(CSSPropertyFontSize);
         }
     }
 }
 
-static void diffTextDecorations(MutableStylePropertySet* style, CSSPropertyID propertID, CSSValue* refTextDecoration)
+static void diffTextDecorations(MutableStylePropertySet* style, CSSPropertyID propertyID, NullableCSSValue refTextDecoration)
 {
-    RefPtrWillBeRawPtr<CSSValue> textDecoration = style->getPropertyCSSValue(propertID);
+    NullableCSSValue textDecoration = style->getPropertyCSSValue(propertyID);
     if (!textDecoration || !textDecoration->isValueList() || !refTextDecoration || !refTextDecoration->isValueList())
         return;
 
-    RefPtrWillBeRawPtr<CSSValueList> newTextDecoration = toCSSValueList(textDecoration.get())->copy();
+    RefPtrWillBeRawPtr<CSSValueList> newTextDecoration = toCSSValueList(textDecoration)->copy();
     CSSValueList* valuesInRefTextDecoration = toCSSValueList(refTextDecoration);
 
     for (size_t i = 0; i < valuesInRefTextDecoration->length(); i++)
         newTextDecoration->removeAll(valuesInRefTextDecoration->item(i));
 
-    setTextDecorationProperty(style, newTextDecoration.get(), propertID);
+    setTextDecorationProperty(style, newTextDecoration.get(), propertyID);
 }
 
-static bool fontWeightIsBold(CSSValue* fontWeight)
+static bool fontWeightIsBold(CSSValue fontWeight)
 {
-    if (!fontWeight->isPrimitiveValue())
+    if (!fontWeight.isPrimitiveValue())
         return false;
 
     // Because b tag can only bold text, there are only two states in plain html: bold and not bold.
     // Collapse all other values to either one of these two states for editing purposes.
-    switch (toCSSPrimitiveValue(fontWeight)->getValueID()) {
+    switch (toCSSPrimitiveValue(fontWeight).getValueID()) {
         case CSSValue100:
         case CSSValue200:
         case CSSValue300:
         case CSSValue400:
         case CSSValue500:
         case CSSValueNormal:
             return false;
         case CSSValueBold:
         case CSSValue600:
         case CSSValue700:
         case CSSValue800:
         case CSSValue900:
             return true;
         default:
             break;
     }
 
     ASSERT_NOT_REACHED(); // For CSSValueBolder and CSSValueLighter
     return false;
 }
 
-static bool fontWeightNeedsResolving(CSSValue* fontWeight)
+static bool fontWeightNeedsResolving(CSSValue fontWeight)
 {
-    if (!fontWeight->isPrimitiveValue())
+    if (!fontWeight.isPrimitiveValue())
         return true;
 
-    CSSValueID value = toCSSPrimitiveValue(fontWeight)->getValueID();
+    CSSValueID value = toCSSPrimitiveValue(fontWeight).getValueID();
     return value == CSSValueLighter || value == CSSValueBolder;
 }
 
 PassRefPtrWillBeRawPtr<MutableStylePropertySet> getPropertiesNotIn(StylePropertySet* styleWithRedundantProperties, CSSStyleDeclaration* baseStyle)
 {
     ASSERT(styleWithRedundantProperties);
     ASSERT(baseStyle);
     RefPtrWillBeRawPtr<MutableStylePropertySet> result = styleWithRedundantProperties->mutableCopy();
 
     result->removeEquivalentProperties(baseStyle);
 
-    RefPtrWillBeRawPtr<CSSValue> baseTextDecorationsInEffect = baseStyle->getPropertyCSSValueInternal(CSSPropertyWebkitTextDecorationsInEffect);
-    diffTextDecorations(result.get(), textDecorationPropertyForEditing(), baseTextDecorationsInEffect.get());
-    diffTextDecorations(result.get(), CSSPropertyWebkitTextDecorationsInEffect, baseTextDecorationsInEffect.get());
+    NullableCSSValue baseTextDecorationsInEffect = baseStyle->getPropertyCSSValueInternal(CSSPropertyWebkitTextDecorationsInEffect);
+    diffTextDecorations(result.get(), textDecorationPropertyForEditing(), baseTextDecorationsInEffect);
+    diffTextDecorations(result.get(), CSSPropertyWebkitTextDecorationsInEffect, baseTextDecorationsInEffect);
 
-    if (RefPtrWillBeRawPtr<CSSValue> baseFontWeight = baseStyle->getPropertyCSSValueInternal(CSSPropertyFontWeight)) {
-        if (RefPtrWillBeRawPtr<CSSValue> fontWeight = result->getPropertyCSSValue(CSSPropertyFontWeight)) {
-            if (!fontWeightNeedsResolving(fontWeight.get()) && (fontWeightIsBold(fontWeight.get()) == fontWeightIsBold(baseFontWeight.get())))
+    if (NullableCSSValue baseFontWeight = baseStyle->getPropertyCSSValueInternal(CSSPropertyFontWeight)) {
+        if (NullableCSSValue fontWeight = result->getPropertyCSSValue(CSSPropertyFontWeight)) {
+            if (!fontWeightNeedsResolving(*fontWeight) && (fontWeightIsBold(*fontWeight) == fontWeightIsBold(*baseFontWeight)))
                 result->removeProperty(CSSPropertyFontWeight);
         }
     }
 
     if (baseStyle->getPropertyCSSValueInternal(CSSPropertyColor) && getRGBAFontColor(result.get()) == getRGBAFontColor(baseStyle))
         result->removeProperty(CSSPropertyColor);
 
     if (baseStyle->getPropertyCSSValueInternal(CSSPropertyTextAlign)
         && textAlignResolvingStartAndEnd(result.get()) == textAlignResolvingStartAndEnd(baseStyle))
         result->removeProperty(CSSPropertyTextAlign);
 
     if (baseStyle->getPropertyCSSValueInternal(CSSPropertyBackgroundColor) && getRGBABackgroundColor(result.get()) == getRGBABackgroundColor(baseStyle))
         result->removeProperty(CSSPropertyBackgroundColor);
 
     return result.release();
 }
 
 CSSValueID getIdentifierValue(StylePropertySet* style, CSSPropertyID propertyID)
 {
     if (!style)
         return CSSValueInvalid;
-    RefPtrWillBeRawPtr<CSSValue> value = style->getPropertyCSSValue(propertyID);
+    NullableCSSValue value = style->getPropertyCSSValue(propertyID);
     if (!value || !value->isPrimitiveValue())
         return CSSValueInvalid;
-    return toCSSPrimitiveValue(value.get())->getValueID();
+    return toCSSPrimitiveValue(value)->getValueID();
 }
 
 CSSValueID getIdentifierValue(CSSStyleDeclaration* style, CSSPropertyID propertyID)
 {
     if (!style)
         return CSSValueInvalid;
-    RefPtrWillBeRawPtr<CSSValue> value = style->getPropertyCSSValueInternal(propertyID);
+    NullableCSSValue value = style->getPropertyCSSValueInternal(propertyID);
     if (!value || !value->isPrimitiveValue())
         return CSSValueInvalid;
-    return toCSSPrimitiveValue(value.get())->getValueID();
+    return toCSSPrimitiveValue(value)->getValueID();
 }
 
 int legacyFontSizeFromCSSValue(Document* document, CSSPrimitiveValue* value, bool isMonospaceFont, LegacyFontSizeMode mode)
 {
     CSSPrimitiveValue::LengthUnitType lengthType;
     if (CSSPrimitiveValue::unitTypeToLengthUnitType(value->primitiveType(), lengthType)
         && lengthType == CSSPrimitiveValue::UnitTypePixels) {
         double conversion = CSSPrimitiveValue::conversionToCanonicalUnitsScaleFactor(value->primitiveType());
         int pixelFontSize = clampTo<int>(value->getDoubleValue() * conversion);
         int legacyFontSize = FontSize::legacyFontSize(document, pixelFontSize, isMonospaceFont);
         // Use legacy font size only if pixel value matches exactly to that of legacy font size.
         if (mode == AlwaysUseLegacyFontSize || FontSize::fontSizeForKeyword(document, legacyFontSize, isMonospaceFont) == pixelFontSize)
             return legacyFontSize;
 
         return 0;
     }
 
     if (CSSValueXSmall <= value->getValueID() && value->getValueID() <= CSSValueWebkitXxxLarge)
         return value->getValueID() - CSSValueXSmall + 1;
 
     return 0;
 }
 
-bool isTransparentColorValue(CSSValue* cssValue)
+bool isTransparentColorValue(NullableCSSValue cssValue)
 {
     if (!cssValue)
         return true;
     if (!cssValue->isPrimitiveValue())
         return false;
     CSSPrimitiveValue* value = toCSSPrimitiveValue(cssValue);
     if (value->isRGBColor())
         return !alphaChannel(value->getRGBA32Value());
     return value->getValueID() == CSSValueTransparent;
 }
 
 bool hasTransparentBackgroundColor(CSSStyleDeclaration* style)
 {
-    RefPtrWillBeRawPtr<CSSValue> cssValue = style->getPropertyCSSValueInternal(CSSPropertyBackgroundColor);
-    return isTransparentColorValue(cssValue.get());
+    NullableCSSValue cssValue = style->getPropertyCSSValueInternal(CSSPropertyBackgroundColor);
+    return isTransparentColorValue(cssValue);
 }
 
 bool hasTransparentBackgroundColor(StylePropertySet* style)
 {
-    RefPtrWillBeRawPtr<CSSValue> cssValue = style->getPropertyCSSValue(CSSPropertyBackgroundColor);
-    return isTransparentColorValue(cssValue.get());
+    NullableCSSValue cssValue = style->getPropertyCSSValue(CSSPropertyBackgroundColor);
+    return isTransparentColorValue(cssValue);
 }
 
-PassRefPtrWillBeRawPtr<CSSValue> backgroundColorInEffect(Node* node)
+NullableCSSValue backgroundColorInEffect(Node* node)
 {
     for (Node* ancestor = node; ancestor; ancestor = ancestor->parentNode()) {
         RefPtrWillBeRawPtr<CSSComputedStyleDeclaration> ancestorStyle = CSSComputedStyleDeclaration::create(ancestor);
         if (!hasTransparentBackgroundColor(ancestorStyle.get()))
             return ancestorStyle->getPropertyCSSValue(CSSPropertyBackgroundColor);
     }
     return nullptr;
 }
 
 }