Get rid of all the library tags.

lib/src/frontend/throws_matcher.dart

 // Copyright (c) 2014, 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.
 
-library test.frontend.throws_matcher;
-
 import 'dart:async';
 
 import 'package:matcher/matcher.dart';
 
 import '../backend/invoker.dart';
 import '../utils.dart';
 import 'expect.dart';
 
 /// This can be used to match two kinds of objects:
 ///
@@ skipping 87 matching lines @@
       mismatchDescription
           .add('threw ')
           .addDescriptionOf(matchState['exception']);
       if (verbose) {
         mismatchDescription.add(' at ').add(matchState['stack'].toString());
       }
       return mismatchDescription;
     }
   }
 }