CSS Properties and Values API: Implement computation / computational independence

third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
index 1bc0a649f87fa512c378d544cfd6871b4eb3d722..720720ab0454a10f73fd2c94d17d0825a7b532f6 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
@@ -1103,7 +1103,22 @@ PassRefPtr<StylePath> StyleBuilderConverter::convertPathOrNone(StyleResolverStat
 
 const CSSValue& StyleBuilderConverter::convertRegisteredPropertyValue(const StyleResolverState& state, const CSSValue& value)
 {
-    // TODO(timloh): Resolve ems, etc.
+    // TODO(timloh): Images and transform-function values can also contain lengths.
+    if (value.isValueList()) {
+        CSSValueList* newList = CSSValueList::createSpaceSeparated();
+        for (const CSSValue* innerValue : toCSSValueList(value))
+            newList->append(convertRegisteredPropertyValue(state, *innerValue));
+        return *newList;
+    }
+
+    if (value.isPrimitiveValue()) {
+        const CSSPrimitiveValue& primitiveValue = toCSSPrimitiveValue(value);
+        if (primitiveValue.isCalculated() || CSSPrimitiveValue::isRelativeUnit(primitiveValue.typeWithCalcResolved())) {
+            // Instead of the actual zoom, use 1 to avoid potential rounding errors
+            Length length = primitiveValue.convertToLength(state.cssToLengthConversionData().copyWithAdjustedZoom(1));
+            return *CSSPrimitiveValue::create(length, 1);
+        }
+    }
     return value;
 }