Fix for opening SDK sources.

pkg/analysis_server/test/domain_analysis_test.dart

Index: pkg/analysis_server/test/domain_analysis_test.dart
diff --git a/pkg/analysis_server/test/domain_analysis_test.dart b/pkg/analysis_server/test/domain_analysis_test.dart
index a18dc3af17b41ca6fa698f6414a142b328a96187..78676ada9ebd81a0234584a76922a4942f99c914 100644
--- a/pkg/analysis_server/test/domain_analysis_test.dart
+++ b/pkg/analysis_server/test/domain_analysis_test.dart
@@ -282,6 +282,23 @@ void test_setSubscriptions() {
       });
     });
   });
+
+  test('after analysis, SDK file', () {
+    AnalysisTestHelper helper = new AnalysisTestHelper();
+    helper.createSingleFileProject('''
+main() {
+  print(42);
+}
+''');
+    return helper.waitForOperationsFinished().then((_) {
+      String file = '/lib/core/core.dart';
+      helper.addAnalysisSubscriptionNavigation(file);
+      return helper.waitForOperationsFinished().then((_) {
+        var navigationRegions = helper.getNavigation(file);
+        expect(navigationRegions, isNot(isEmpty));
+      });
+    });
+  });
 }