CSSStyleDeclaration::setProperty should override important style

Source/core/editing/EditingStyle.cpp

Index: Source/core/editing/EditingStyle.cpp
diff --git a/Source/core/editing/EditingStyle.cpp b/Source/core/editing/EditingStyle.cpp
index bcdf821ebcf47078eec5c81e2d73e9ea4f6f858b..b4b6102ca1e48af6f42c4bf26bb0e7b5754045eb 100644
--- a/Source/core/editing/EditingStyle.cpp
+++ b/Source/core/editing/EditingStyle.cpp
@@ -1173,7 +1173,7 @@ void EditingStyle::mergeStyleFromRulesForSerialization(Element* element)
                 continue;
             if (toCSSPrimitiveValue(value)->isPercentage()) {
                 if (RefPtrWillBeRawPtr<CSSValue> computedPropertyValue = computedStyleForElement->getPropertyCSSValue(property.id()))
-                    fromComputedStyle->addParsedProperty(CSSProperty(property.id(), computedPropertyValue));
+                    fromComputedStyle->addRespectingCascade(CSSProperty(property.id(), computedPropertyValue));
             }
         }
     }