Remove library tags, they aren't needed

lib/src/report.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Summarizes the information produced by the checker.
-library dev_compiler.src.report;
 
 import 'dart:math' show max;
 
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:analyzer/src/generated/error.dart';
 import 'package:logging/logging.dart';
 import 'package:path/path.dart' as path;
 import 'package:source_span/source_span.dart';
 
 import 'utils.dart';
@@ skipping 344 matching lines @@
 
   visitMessage(MessageSummary message) {
     var kind = message.kind;
     errorCount.putIfAbsent(currentPackage, () => <String, int>{});
     errorCount[currentPackage].putIfAbsent(kind, () => 0);
     errorCount[currentPackage][kind]++;
     totals.putIfAbsent(kind, () => 0);
     totals[kind]++;
   }
 }