CSS Custom Properties (Variables)

Source/core/css/resolver/StyleBuilderCustom.cpp

Index: Source/core/css/resolver/StyleBuilderCustom.cpp
diff --git a/Source/core/css/resolver/StyleBuilderCustom.cpp b/Source/core/css/resolver/StyleBuilderCustom.cpp
index ff629ab79e437a58c16a05f4d9d724c6861f07c9..3e5d887f61e5dfda7fd20e3026e2dbcf48de0701 100644
--- a/Source/core/css/resolver/StyleBuilderCustom.cpp
+++ b/Source/core/css/resolver/StyleBuilderCustom.cpp
@@ -44,6 +44,7 @@
 #include "core/StylePropertyShorthand.h"
 #include "core/css/BasicShapeFunctions.h"
 #include "core/css/CSSCursorImageValue.h"
+#include "core/css/CSSCustomVariableValue.h"
 #include "core/css/CSSGradientValue.h"
 #include "core/css/CSSGridTemplateAreasValue.h"
 #include "core/css/CSSHelper.h"
@@ -56,6 +57,10 @@
 #include "core/css/Pair.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/StyleRule.h"
+#include "core/css/parser/CSSParser.h"
+#include "core/css/parser/CSSParserTokenRange.h"
+#include "core/css/parser/CSSPropertyParser.h"
+#include "core/css/resolver/CSSVariableResolver.h"
 #include "core/css/resolver/ElementStyleResources.h"
 #include "core/css/resolver/FilterOperationResolver.h"
 #include "core/css/resolver/FontBuilder.h"
@@ -106,6 +111,11 @@ static inline bool isValidVisitedLinkProperty(CSSPropertyID id)
 
 void StyleBuilder::applyProperty(CSSPropertyID id, StyleResolverState& state, CSSValue* value)
 {
+    if (RuntimeEnabledFeatures::cssVariablesEnabled() && id != CSSPropertyVariable && value->isPrimitiveValue() && toCSSPrimitiveValue(value)->isVariableReference()) {
+        CSSVariableResolver::resolveAndApplyVariableReferences(state, id, toCSSPrimitiveValue(value));
+        return;
+    }
+
     ASSERT_WITH_MESSAGE(!isShorthandProperty(id), "Shorthand property id = %d wasn't expanded at parsing time", id);
 
     bool isInherit = state.parentNode() && value->isInheritedValue();
@@ -799,6 +809,45 @@ void StyleBuilderFunctions::applyValueCSSPropertyWebkitTextOrientation(StyleReso
     state.setTextOrientation(*toCSSPrimitiveValue(value));
 }
 
+void StyleBuilderFunctions::applyValueCSSPropertyVariable(StyleResolverState& state, CSSValue* value)
+{
+    CSSCustomVariableValue* varVal = toCSSCustomVariableValue(value);
+    switch (varVal->id()) {
+    case CSSValueInitial:
+        state.style()->removeVariable(varVal->name());
+        break;
+
+    case CSSValueUnset:
+        state.style()->removeVariable(varVal->name());
+        // Intentional fallthrough.
+    case CSSValueInherit: {
+        StyleVariableData* parentVariables = state.parentStyle()->variables();
+        if (!parentVariables)
+            return;
+        CSSVariableData* value = parentVariables->getVariable(varVal->name());
+        if (!value)
+            return;
+        state.style()->setVariable(varVal->name(), value);
+        break;
+    }
+    case CSSValueInternalVariableValue:
+        state.style()->setVariable(varVal->name(), varVal->value());
+        break;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
+void StyleBuilderFunctions::applyInheritCSSPropertyVariable(StyleResolverState& state)
+{
+    // We reach this via the 'all' property, which does not apply to variables
+}
+
+void StyleBuilderFunctions::applyInitialCSSPropertyVariable(StyleResolverState& state)
+{
+    ASSERT_NOT_REACHED();
+}
+
 void StyleBuilderFunctions::applyInheritCSSPropertyBaselineShift(StyleResolverState& state)
 {
     const SVGComputedStyle& parentSvgStyle = state.parentStyle()->svgStyle();