Make UseCounters work on aliased properties

Source/core/css/ComputedStyleCSSValueMapping.cpp

Index: Source/core/css/ComputedStyleCSSValueMapping.cpp
diff --git a/Source/core/css/ComputedStyleCSSValueMapping.cpp b/Source/core/css/ComputedStyleCSSValueMapping.cpp
index 00dd034597ae67f7a1855dc7fa9d2efbf16236f6..4c162008132be99a1ff4e269017b64378c603d78 100644
--- a/Source/core/css/ComputedStyleCSSValueMapping.cpp
+++ b/Source/core/css/ComputedStyleCSSValueMapping.cpp
@@ -960,7 +960,7 @@ static PassRefPtrWillBeRawPtr<CSSValue> createTransitionPropertyValue(const CSST
     if (property.propertyType == CSSTransitionData::TransitionUnknown)
         return cssValuePool().createValue(property.propertyString, CSSPrimitiveValue::CSS_CUSTOM_IDENT);
     ASSERT(property.propertyType == CSSTransitionData::TransitionSingleProperty);
-    return cssValuePool().createValue(getPropertyNameString(property.propertyId), CSSPrimitiveValue::CSS_CUSTOM_IDENT);
+    return cssValuePool().createValue(getPropertyNameString(property.unresolvedProperty), CSSPrimitiveValue::CSS_CUSTOM_IDENT);
 }
 
 static PassRefPtrWillBeRawPtr<CSSValue> valueForTransitionProperty(const CSSTransitionData* transitionData)
@@ -2573,6 +2573,8 @@ PassRefPtrWillBeRawPtr<CSSValue> ComputedStyleCSSValueMapping::get(CSSPropertyID
 
     case CSSPropertyAll:
         return nullptr;
+    default:
+        break;
     }
     ASSERT_NOT_REACHED();
     return nullptr;