Resubmission of sashab's patch: Make CSSComputedStyledeclaration::getPropertyCSSValue return const

Make CSSComputedStyledeclaration::getPropertyCSSValue() return a const
CSSValue* instead of a regular CSSValue*. This required changing
CSSStyleDeclaration::getPropertyCSSValueInternal() return a const
CSSValue* as well, and marking CSSValueList::copy() as a const method
(which it already was, it was just missing the const modifier). This is
pre-work for making CSSValueList store const CSSValues.

This patch is mostly mechanical changes, but does contain one logic
change: the static method mergeTextDecorationValues in EditingStyle
needs to be changed since it modifies a CSSValueList that points inside
the mutable style. Instead, the function is changed to take two
CSSValueLists and return a new one, and the callsite is changed to
replace the old CSSValueList with the new one in the style rather than
modifying the old CSSValueList in-place.

Original patch is here:
https://codereview.chromium.org/2034013002

BUG=526586

Review-Url: https://codereview.chromium.org/2046463003
Cr-Commit-Position: refs/heads/master@{#398235}

third_party/WebKit/Source/bindings/core/v8/custom/V8CSSStyleDeclarationCustom.cpp

@@ -195,7 +195,7 @@ void V8CSSStyleDeclaration::namedPropertyGetterCustom(v8::Local<v8::Name> name,
 
     CSSStyleDeclaration* impl = V8CSSStyleDeclaration::toImpl(info.Holder());
     // TODO(leviw): This API doesn't support custom properties.
-    CSSValue* cssValue = impl->getPropertyCSSValueInternal(resolvedProperty);
+    const CSSValue* cssValue = impl->getPropertyCSSValueInternal(resolvedProperty);
     if (cssValue) {
         v8SetReturnValueStringOrNull(info, cssValue->cssText(), info.GetIsolate());
         return;

third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp

@@ -401,7 +401,7 @@ inline static CSSPrimitiveValue* zoomAdjustedPixelValue(double value, const Comp
     return CSSPrimitiveValue::create(adjustFloatForAbsoluteZoom(value, style), CSSPrimitiveValue::UnitType::Pixels);
 }
 
-CSSValue* CSSComputedStyleDeclaration::getFontSizeCSSValuePreferringKeyword() const
+const CSSValue* CSSComputedStyleDeclaration::getFontSizeCSSValuePreferringKeyword() const
 {
     if (!m_node)
         return nullptr;
@@ -514,7 +514,7 @@ Node* CSSComputedStyleDeclaration::styledNode() const
     return m_node.get();
 }
 
-CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValue(AtomicString customPropertyName) const
+const CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValue(AtomicString customPropertyName) const
 {
     Node* styledNode = this->styledNode();
     if (!styledNode)
@@ -536,7 +536,7 @@ std::unique_ptr<HashMap<AtomicString, RefPtr<CSSVariableData>>> CSSComputedStyle
     return ComputedStyleCSSValueMapping::getVariables(*style);
 }
 
-CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValue(CSSPropertyID propertyID) const
+const CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValue(CSSPropertyID propertyID) const
 {
     Node* styledNode = this->styledNode();
     if (!styledNode)
@@ -576,7 +576,7 @@ CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValue(CSSPropertyID propert
 
 String CSSComputedStyleDeclaration::getPropertyValue(CSSPropertyID propertyID) const
 {
-    CSSValue* value = getPropertyCSSValue(propertyID);
+    const CSSValue* value = getPropertyCSSValue(propertyID);
     if (value)
         return value->cssText();
     return "";
@@ -610,7 +610,7 @@ bool CSSComputedStyleDeclaration::cssPropertyMatches(CSSPropertyID propertyID, c
                 return true;
         }
     }
-    CSSValue* value = getPropertyCSSValue(propertyID);
+    const CSSValue* value = getPropertyCSSValue(propertyID);
     return value && propertyValue && value->equals(*propertyValue);
 }
 
@@ -624,7 +624,7 @@ MutableStylePropertySet* CSSComputedStyleDeclaration::copyPropertiesInSet(const
     HeapVector<CSSProperty, 256> list;
     list.reserveInitialCapacity(properties.size());
     for (unsigned i = 0; i < properties.size(); ++i) {
-        CSSValue* value = getPropertyCSSValue(properties[i]);
+        const CSSValue* value = getPropertyCSSValue(properties[i]);
         if (value)
             list.append(CSSProperty(properties[i], value, false));
     }
@@ -641,7 +641,7 @@ String CSSComputedStyleDeclaration::getPropertyValue(const String& propertyName)
     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (!propertyID) {
         if (RuntimeEnabledFeatures::cssVariablesEnabled() && CSSVariableParser::isValidVariableName(propertyName)) {
-            CSSValue* value = getPropertyCSSValue(AtomicString(propertyName));
+            const CSSValue* value = getPropertyCSSValue(AtomicString(propertyName));
             if (value)
                 return value->cssText();
         }
@@ -678,7 +678,7 @@ String CSSComputedStyleDeclaration::removeProperty(const String& name, Exception
     return String();
 }
 
-CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValueInternal(CSSPropertyID propertyID)
+const CSSValue* CSSComputedStyleDeclaration::getPropertyCSSValueInternal(CSSPropertyID propertyID)
 {
     return getPropertyCSSValue(propertyID);
 }

third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.h

@@ -58,11 +58,11 @@ public:
 
     MutableStylePropertySet* copyProperties() const;
 
-    CSSValue* getPropertyCSSValue(CSSPropertyID) const;
-    CSSValue* getPropertyCSSValue(AtomicString customPropertyName) const;
+    const CSSValue* getPropertyCSSValue(CSSPropertyID) const;
+    const CSSValue* getPropertyCSSValue(AtomicString customPropertyName) const;
     std::unique_ptr<HashMap<AtomicString, RefPtr<CSSVariableData>>> getVariables() const;
 
-    CSSValue* getFontSizeCSSValuePreferringKeyword() const;
+    const CSSValue* getFontSizeCSSValuePreferringKeyword() const;
     bool isMonospaceFont() const;
 
     MutableStylePropertySet* copyPropertiesInSet(const Vector<CSSPropertyID>&) const;
@@ -94,7 +94,7 @@ private:
     void setCSSFloat(const String&, ExceptionState&);
     String cssText() const override;
     void setCSSText(const String&, ExceptionState&) override;
-    CSSValue* getPropertyCSSValueInternal(CSSPropertyID) override;
+    const CSSValue* getPropertyCSSValueInternal(CSSPropertyID) override;
     String getPropertyValueInternal(CSSPropertyID) override;
     void setPropertyInternal(CSSPropertyID, const String& customPropertyName, const String& value, bool important, ExceptionState&) override;
 

third_party/WebKit/Source/core/css/CSSStyleDeclaration.h

@@ -65,7 +65,7 @@ public:
     // CSSPropertyID versions of the CSSOM functions to support bindings and editing.
     // Use the non-virtual methods in the concrete subclasses when possible.
     // The CSSValue returned by this function should not be exposed to the web as it may be used by multiple documents at the same time.
-    virtual CSSValue* getPropertyCSSValueInternal(CSSPropertyID) = 0;
+    virtual const CSSValue* getPropertyCSSValueInternal(CSSPropertyID) = 0;
     virtual String getPropertyValueInternal(CSSPropertyID) = 0;
     virtual void setPropertyInternal(CSSPropertyID, const String& propertyValue, const String& value, bool important, ExceptionState&) = 0;
 

third_party/WebKit/Source/core/css/CSSValueList.cpp

@@ -62,7 +62,7 @@ bool CSSValueList::hasValue(const CSSValue& val) const
     return false;
 }
 
-CSSValueList* CSSValueList::copy()
+CSSValueList* CSSValueList::copy() const
 {
     CSSValueList* newList = nullptr;
     switch (m_valueListSeparator) {

third_party/WebKit/Source/core/css/CSSValueList.h

@@ -63,7 +63,7 @@ public:
     void append(CSSValue* value) { m_values.append(value); }
     bool removeAll(const CSSValue&);
     bool hasValue(const CSSValue&) const;
-    CSSValueList* copy();
+    CSSValueList* copy() const;
 
     String customCSSText() const;
     bool equals(const CSSValueList&) const;

third_party/WebKit/Source/core/css/PropertySetCSSStyleDeclaration.cpp

@@ -258,7 +258,7 @@ String AbstractPropertySetCSSStyleDeclaration::removeProperty(const String& prop
     return result;
 }
 
-CSSValue* AbstractPropertySetCSSStyleDeclaration::getPropertyCSSValueInternal(CSSPropertyID propertyID)
+const CSSValue* AbstractPropertySetCSSStyleDeclaration::getPropertyCSSValueInternal(CSSPropertyID propertyID)
 {
     return propertySet().getPropertyCSSValue(propertyID);
 }

third_party/WebKit/Source/core/css/PropertySetCSSStyleDeclaration.h

@@ -60,7 +60,7 @@ private:
     void setCSSFloat(const String&, ExceptionState&);
     String cssText() const final;
     void setCSSText(const String&, ExceptionState&) final;
-    CSSValue* getPropertyCSSValueInternal(CSSPropertyID) final;
+    const CSSValue* getPropertyCSSValueInternal(CSSPropertyID) final;
     String getPropertyValueInternal(CSSPropertyID) final;
     void setPropertyInternal(CSSPropertyID, const String& customPropertyName, const String& value, bool important, ExceptionState&) final;
 

third_party/WebKit/Source/core/css/cssom/ComputedStylePropertyMap.cpp

@@ -11,7 +11,7 @@ namespace blink {
 
 StylePropertyMap::StyleValueVector ComputedStylePropertyMap::getAll(CSSPropertyID propertyID)
 {
-    CSSValue* cssValue = m_computedStyleDeclaration->getPropertyCSSValueInternal(propertyID);
+    const CSSValue* cssValue = m_computedStyleDeclaration->getPropertyCSSValueInternal(propertyID);
     if (!cssValue)
         return StylePropertyMap::StyleValueVector();
     return cssValueToStyleValueVector(propertyID, *cssValue);

third_party/WebKit/Source/core/editing/commands/ApplyStyleCommand.cpp

@@ -1682,7 +1682,7 @@ float ApplyStyleCommand::computedFontSize(Node* node)
     if (!style)
         return 0;
 
-    CSSPrimitiveValue* value = toCSSPrimitiveValue(style->getPropertyCSSValue(CSSPropertyFontSize));
+    const CSSPrimitiveValue* value = toCSSPrimitiveValue(style->getPropertyCSSValue(CSSPropertyFontSize));
     if (!value)
         return 0;
 

third_party/WebKit/Source/core/inspector/LayoutEditor.cpp

@@ -187,20 +187,20 @@ void LayoutEditor::rebuild()
     editableSelectorUpdated(false);
 }
 
-CSSPrimitiveValue* LayoutEditor::getPropertyCSSValue(CSSPropertyID property) const
+const CSSPrimitiveValue* LayoutEditor::getPropertyCSSValue(CSSPropertyID property) const
 {
     CSSStyleDeclaration* style = m_cssAgent->findEffectiveDeclaration(property, m_matchedStyles);
     if (!style)
         return nullptr;
 
-    CSSValue* cssValue = style->getPropertyCSSValueInternal(property);
+    const CSSValue* cssValue = style->getPropertyCSSValueInternal(property);
     if (!cssValue || !cssValue->isPrimitiveValue())
         return nullptr;
 
     return toCSSPrimitiveValue(cssValue);
 }
 
-bool LayoutEditor::growInside(String propertyName, CSSPrimitiveValue* value)
+bool LayoutEditor::growInside(String propertyName, const CSSPrimitiveValue* value)
 {
     FloatQuad content1, padding1, border1, margin1;
     InspectorHighlight::buildNodeQuads(m_element.get(), &content1, &padding1, &border1, &margin1);
@@ -254,7 +254,7 @@ bool LayoutEditor::growInside(String propertyName, CSSPrimitiveValue* value)
 
 std::unique_ptr<protocol::DictionaryValue> LayoutEditor::createValueDescription(const String& propertyName)
 {
-    CSSPrimitiveValue* cssValue = getPropertyCSSValue(cssPropertyID(propertyName));
+    const CSSPrimitiveValue* cssValue = getPropertyCSSValue(cssPropertyID(propertyName));
     if (cssValue && !(cssValue->isLength() || cssValue->isPercentage()))
         return nullptr;
 
@@ -284,7 +284,7 @@ void LayoutEditor::overlayStartedPropertyChange(const String& anchorName)
     if (!m_changingProperty)
         return;
 
-    CSSPrimitiveValue* cssValue = getPropertyCSSValue(m_changingProperty);
+    const CSSPrimitiveValue* cssValue = getPropertyCSSValue(m_changingProperty);
     m_valueUnitType = cssValue ? cssValue->typeWithCalcResolved() : CSSPrimitiveValue::UnitType::Pixels;
     if (!isMutableUnitType(m_valueUnitType))
         return;

third_party/WebKit/Source/core/inspector/LayoutEditor.h

@@ -45,14 +45,14 @@ public:
 
 private:
     LayoutEditor(Element*, InspectorCSSAgent*, InspectorDOMAgent*, ScriptController*);
-    CSSPrimitiveValue* getPropertyCSSValue(CSSPropertyID) const;
+    const CSSPrimitiveValue* getPropertyCSSValue(CSSPropertyID) const;
     std::unique_ptr<protocol::DictionaryValue> createValueDescription(const String&);
     void appendAnchorFor(protocol::ListValue*, const String&, const String&);
     bool setCSSPropertyValueInCurrentRule(const String&);
     void editableSelectorUpdated(bool hasChanged) const;
     void evaluateInOverlay(const String&, std::unique_ptr<protocol::Value>) const;
     std::unique_ptr<protocol::DictionaryValue> currentSelectorInfo(CSSStyleDeclaration*) const;
-    bool growInside(String propertyName, CSSPrimitiveValue*);
+    bool growInside(String propertyName, const CSSPrimitiveValue*);
 
     Member<Element> m_element;
     Member<InspectorCSSAgent> m_cssAgent;