Revert "Fix x.runtimeType for native classes"

sdk/lib/_internal/compiler/implementation/lib/interceptors.dart

Index: sdk/lib/_internal/compiler/implementation/lib/interceptors.dart
diff --git a/sdk/lib/_internal/compiler/implementation/lib/interceptors.dart b/sdk/lib/_internal/compiler/implementation/lib/interceptors.dart
index d56fb0bc5632f5e752d01272e5c006e9ea761ace..4c316881ef265a1e89a4b459a71efb408c257274 100644
--- a/sdk/lib/_internal/compiler/implementation/lib/interceptors.dart
+++ b/sdk/lib/_internal/compiler/implementation/lib/interceptors.dart
@@ -15,13 +15,14 @@ import 'dart:_js_helper' show allMatchesInStringUnchecked,
                               checkNull,
                               checkNum,
                               checkString,
-                              getRuntimeType,
+                              getRuntimeTypeString,
                               regExpGetNative,
                               stringContainsUnchecked,
                               stringLastIndexOfUnchecked,
                               stringReplaceAllFuncUnchecked,
                               stringReplaceAllUnchecked,
                               stringReplaceFirstUnchecked,
+                              TypeImpl,
                               lookupDispatchRecord;
 import 'dart:_foreign_helper' show JS;
 
@@ -209,7 +210,7 @@ abstract class Interceptor {
                                 invocation.namedArguments);
   }
 
-  Type get runtimeType => getRuntimeType(this);
+  Type get runtimeType;
 }
 
 /**