Add navigation region for 'library' directives.

pkg/analysis_server/test/analysis/notification_navigation_test.dart

Index: pkg/analysis_server/test/analysis/notification_navigation_test.dart
diff --git a/pkg/analysis_server/test/analysis/notification_navigation_test.dart b/pkg/analysis_server/test/analysis/notification_navigation_test.dart
index 41f3a6ff8d55a2c268fde896017c4a8255819caa..fee0d6f8a60ea36005eee60f101f8b4456060b03 100644
--- a/pkg/analysis_server/test/analysis/notification_navigation_test.dart
+++ b/pkg/analysis_server/test/analysis/notification_navigation_test.dart
@@ -103,6 +103,14 @@ class AbstractNavigationTest extends AbstractAnalysisTest {
   }
 
   /**
+   * Validates that there is a target in [testTargets]  with [testFile], at the
+   * offset of [str] in [testFile], and with the length of  [str].
+   */
+  void assertHasTargetString(String str) {
+    assertHasTarget(str, str.length);
+  }
+
+  /**
    * Validates that there is no a region at [search] and with the given
    * [length].
    */
@@ -581,6 +589,16 @@ main() {
     });
   }
 
+  test_library() {
+    addTestFile('''
+library my.lib;
+''');
+    return prepareNavigation().then((_) {
+      assertHasRegionString('my.lib');
+      assertHasTargetString('my.lib');
+    });
+  }
+
   test_multiplyDefinedElement() {
     addFile('$projectPath/bin/libA.dart', 'library A; int TEST = 1;');
     addFile('$projectPath/bin/libB.dart', 'library B; int TEST = 2;');