anchor.diff:      };
     }
   
  +  static const Map<String, String> _kSdkNameToMetricNameMapping = const <String, String> {
  +    'VMIsolate': 'aot_snapshot_size_vmisolate',
  +    'Isolate': 'aot_snapshot_size_isolate',
  +    'ReadOnlyData': 'aot_snapshot_size_rodata',
  +    'Instructions': 'aot_snapshot_size_instructions',
  +    'Total': 'aot_snapshot_size_total',
  +  };
  +
     static String _sdkNameToMetricName(String sdkName) {
  -    const Map<String, String> kSdkNameToMetricNameMapping = const <String, String> {
  -      'VMIsolate': 'aot_snapshot_size_vmisolate',
  -      'Isolate': 'aot_snapshot_size_isolate',
  -      'ReadOnlyData': 'aot_snapshot_size_rodata',
  -      'Instructions': 'aot_snapshot_size_instructions',
  -      'Total': 'aot_snapshot_size_total',
  -    };
  -
  -    if (!kSdkNameToMetricNameMapping.containsKey(sdkName))
  +
  +    if (!_kSdkNameToMetricNameMapping.containsKey(sdkName))
         throw 'Unrecognized SDK snapshot metric name: $sdkName';
   
  -    return kSdkNameToMetricNameMapping[sdkName];
  +    return _kSdkNameToMetricNameMapping[sdkName];
     }
   }
   
  
positive.code:     final Map<String, dynamic> metrics = <String, dynamic>{};
      for (Match m in metricExpression.allMatches(compileLog)) {
        metrics[_sdkNameToMetricName(m.group(1))] = int.parse(m.group(2));
      }
      metrics['aot_snapshot_compile_millis'] = watch.elapsedMilliseconds;
  
  
negative.code:     final List<String> options = <String>[
        'aot',
        '-v',
        '--extra-gen-snapshot-options=--print_snapshot_sizes',
        '--release',
        '--no-pub',
        '--target-platform',
  