Migrate protocol_test.dart to reflective tests.

pkg/analysis_server/test/declarative_tests.dart

-library declarative_tests;
-
-import 'dart:mirrors';
-
-import 'package:unittest/unittest.dart' show group, test;
-
-/**
- * Use [runTest] annotation to indicate that method is a test method.
- * Alternatively method name can have the `test` prefix.
- */
-const runTest = const _RunTest();
-
-class _RunTest {
-  const _RunTest();
-}
-
-/**
- * Creates a new named group of tests with the name of the given [Type], then
- * adds new tests using [addTestMethods].
- */
-addTestSuite(Type type) {
-  group(type.toString(), () {
-    addTestMethods(type);
-  });
-}
-
-/**
- * Creates a new test case for the each static method with the name starting
- * with `test` or having the [runTest] annotation.
- */
-addTestMethods(Type type) {
-  var typeMirror = reflectClass(type);
-  typeMirror.staticMembers.forEach((methodSymbol, method) {
-    if (_isTestMethod(method)) {
-      var methodName = MirrorSystem.getName(methodSymbol);
-      test(methodName, () {
-        typeMirror.invoke(methodSymbol, []);
-      });
-    }
-  });
-}
-
-bool _isTestMethod(MethodMirror method) {
-  if (method.parameters.isNotEmpty) {
-    return false;
-  }
-  var methodSymbol = method.simpleName;
-  // name starts with "test"
-  var methodName = MirrorSystem.getName(methodSymbol);
-  if (methodName.startsWith('test')) {
-    return true;
-  }
-  // has @testMethod
-  return method.metadata.any((annotation) {
-    return identical(annotation.reflectee, runTest);
-  });
-}