Implement SearchEngine.searchTopLevelDeclarations() for the new driver.

pkg/analysis_server/test/services/search/search_engine2_test.dart

Index: pkg/analysis_server/test/services/search/search_engine2_test.dart
diff --git a/pkg/analysis_server/test/services/search/search_engine2_test.dart b/pkg/analysis_server/test/services/search/search_engine2_test.dart
index 13a3c2efd536c607b67fc237877a2512045040b1..eed803e27a3a8cdd7f786a1bf52281ae3b7ba43b 100644
--- a/pkg/analysis_server/test/services/search/search_engine2_test.dart
+++ b/pkg/analysis_server/test/services/search/search_engine2_test.dart
@@ -2,6 +2,8 @@
 // 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 'dart:async';
+
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analysis_server/src/services/search/search_engine_internal2.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ -138,6 +140,51 @@ T b;
         matches, contains(predicate((SearchMatch m) => m.element.name == 'b')));
   }
 
+  test_searchTopLevelDeclarations() async {
+    var a = _p('/test/a.dart');
+    var b = _p('/test/b.dart');
+
+    provider.newFile(
+        a,
+        '''
+class A {}
+int a;
+''');
+    provider.newFile(
+        b,
+        '''
+class B {}
+get b => 42;
+''');
+
+    var driver1 = _newDriver();
+    var driver2 = _newDriver();
+
+    driver1.addFile(a);
+    driver2.addFile(b);
+
+    while (scheduler.isAnalyzing) {
+      await new Future.delayed(new Duration(milliseconds: 1));
+    }
+
+    var searchEngine = new SearchEngineImpl2([driver1, driver2]);
+    List<SearchMatch> matches =
+        await searchEngine.searchTopLevelDeclarations('.*');
+    expect(matches, hasLength(4));
+
+    void assertHasElement(String name) {
+      expect(
+          matches,
+          contains(predicate((SearchMatch m) =>
+              m.kind == MatchKind.DECLARATION && m.element.name == name)));
+    }
+
+    assertHasElement('A');
+    assertHasElement('a');
+    assertHasElement('B');
+    assertHasElement('b');
+  }
+
   AnalysisDriver _newDriver() => new AnalysisDriver(
       scheduler,
       logger,