Add web socket command to stop serving a directory.

sdk/lib/_internal/pub/test/serve/web_socket/unserve_directory_subdirectory_still_watched_test.dart

Index: sdk/lib/_internal/pub/test/serve/web_socket/unserve_directory_subdirectory_still_watched_test.dart
diff --git a/sdk/lib/_internal/pub/test/serve/web_socket/unserve_directory_subdirectory_still_watched_test.dart b/sdk/lib/_internal/pub/test/serve/web_socket/unserve_directory_subdirectory_still_watched_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..c08ff4bf9c8b17d3a0e1cfe2f64edffe804911a5
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+++ b/sdk/lib/_internal/pub/test/serve/web_socket/unserve_directory_subdirectory_still_watched_test.dart
@@ -0,0 +1,61 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.file
+// 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.
+
+library pub_tests;
+
+import 'package:path/path.dart' as p;
+
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+import '../utils.dart';
+
+main() {
+  initConfig();
+  integration("when a subdirectory is unbound it is still watched because the "
+      "superdirectory is watching it", () {
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir("example", [
+        d.dir("one", [
+          d.file("foo.txt", "before")
+        ])
+      ])
+    ]).create();
+
+    var exampleOne = p.join("example", "one");
+    pubServe(args: ["example", exampleOne]);
+
+    requestShouldSucceed("one/foo.txt", "before", root: "example");
+    requestShouldSucceed("foo.txt", "before", root: exampleOne);
+
+    // Unbind the subdirectory.
+    expectWebSocketCall({
+      "command": "unserveDirectory",
+      "path": exampleOne
+    }, replyEquals: {
+      "url": getServerUrl(exampleOne)
+    });
+
+    // "example/one" should not be served now.
+    requestShouldNotConnect("foo.txt", root: exampleOne);
+
+    // "example" is still fine.
+    requestShouldSucceed("one/foo.txt", "before", root: "example");
+
+    // And still being watched.
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir("example", [
+        d.dir("one", [
+          d.file("foo.txt", "after")
+        ])
+      ])
+    ]).create();
+
+    waitForBuildSuccess();
+    requestShouldSucceed("one/foo.txt", "after", root: "example");
+
+    endPubServe();
+  });
+}