Fix tests for pub global activate.

sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart

Index: sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart
diff --git a/sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart b/sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart
index 527f597ab5c5584c9d0d48d3dceb125a8a50318b..60be82ffbe132f27a1ecb3b1c531974b39d6933a 100644
--- a/sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart
+++ b/sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart
@@ -4,8 +4,10 @@
 
 library pub_tests;
 
+import '../../lib/src/exit_codes.dart' as exit_codes;
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
+import '../test_pub.dart';
 
 main() {
   initConfig();
@@ -19,7 +21,8 @@ main() {
       pubCommand(command, error: new RegExp(r"""
 Could not find package foo at http://localhost:\d+\.
 Depended on by:
-- myapp""", multiLine: true));
+- myapp""", multiLine: true),
+          exitCode: exit_codes.UNAVAILABLE);
     });
   });
 }