Strong mode cleaning of many dart2js tests.

tests/compiler/dart2js/reexport_handled_test.dart

 // Copyright (c) 2013, 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 reexport_handled_test;
 
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 import 'mock_compiler.dart';
-import 'package:compiler/src/elements/elements.dart'
-    show Element, LibraryElement;
 
 final exportingLibraryUri = Uri.parse('exporting.dart');
 const String EXPORTING_LIBRARY_SOURCE = '''
 library exporting;
 var foo;
 ''';
 
 final reexportingLibraryUri = Uri.parse('reexporting.dart');
 const String REEXPORTING_LIBRARY_SOURCE = '''
 library reexporting;
@@ skipping 11 matching lines @@
       }).then((loadedLibraries) {
         compiler.processLoadedLibraries(loadedLibraries);
         var exportingLibrary = loadedLibraries.rootLibrary;
         Expect.isTrue(exportingLibrary.exportsHandled);
         var foo = exportingLibrary.findExported('foo');
         Expect.isNotNull(foo);
         Expect.isTrue(foo.isField);
 
         // Load reexporting library when exports are handled on the exporting library.
         return compiler.libraryLoader.loadLibrary(reexportingLibraryUri);
-      }).then((loadedLibraries) {
+      }).then((dynamic loadedLibraries) {
         compiler.processLoadedLibraries(loadedLibraries);
         var foo = loadedLibraries.rootLibrary.findExported('foo');
         Expect.isNotNull(foo);
         Expect.isTrue(foo.isField);
       }));
 }