| Index: sdk/lib/_internal/compiler/js_lib/js_number.dart | 
| diff --git a/sdk/lib/_internal/compiler/js_lib/js_number.dart b/sdk/lib/_internal/compiler/js_lib/js_number.dart | 
| index c1357e02f73026ea9207f32b86a29d26cc44d01b..8ea8a0326c694c326f07ceb8922073e3331b887b 100644 | 
| --- a/sdk/lib/_internal/compiler/js_lib/js_number.dart | 
| +++ b/sdk/lib/_internal/compiler/js_lib/js_number.dart | 
| @@ -57,7 +57,8 @@ class JSNumber extends Interceptor implements num { | 
| return JS('num', r'# % #', this, b); | 
| } | 
|  | 
| -  num abs() => JS('num', r'Math.abs(#)', this); | 
| +  num abs() => JS('returns:num;effects:none;depends:none;throws:never', | 
| +      r'Math.abs(#)', this); | 
|  | 
| num get sign => this > 0 ? 1 : this < 0 ? -1 : this; | 
|  | 
|  |