Switch server tests to strong mode.

pkg/analysis_server/test/plugin/protocol_dart_test.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.
 
 import 'package:analysis_server/plugin/protocol/protocol_dart.dart';
 import 'package:analyzer/dart/ast/ast.dart' as engine;
 import 'package:analyzer/dart/ast/visitor.dart' as engine;
 import 'package:analyzer/dart/element/element.dart' as engine;
 import 'package:analyzer/dart/element/type.dart' as engine;
 import 'package:analyzer/error/error.dart' as engine;
@@ skipping 314 matching lines @@
     expect(element.name, 'myField');
     {
       Location location = element.location;
       expect(location.file, '/test.dart');
       expect(location.offset, 25);
       expect(location.length, 'myField'.length);
       expect(location.startLine, 2);
       expect(location.startColumn, 16);
     }
     expect(element.parameters, isNull);
-    expect(element.returnType, 'dynamic');
+    expect(element.returnType, 'int');
     expect(element.flags, Element.FLAG_CONST | Element.FLAG_STATIC);
   }
 
   test_fromElement_FUNCTION_TYPE_ALIAS() async {
     engine.Source source = addSource(
         '/test.dart',
         '''
 typedef int F<T>(String x);
 ''');
     engine.CompilationUnit unit = await resolveLibraryUnit(source);
@@ skipping 122 matching lines @@
       expect(location.offset, 16);
       expect(location.length, 'mySetter'.length);
       expect(location.startLine, 2);
       expect(location.startColumn, 7);
     }
     expect(element.parameters, '(String x)');
     expect(element.returnType, isNull);
     expect(element.flags, 0);
   }
 }