Compile file_transfer_controller in gyp v2

ui/file_manager/file_manager/foreground/js/webui_command_extender.js

Index: ui/file_manager/file_manager/foreground/js/webui_command_extender.js
diff --git a/ui/file_manager/file_manager/foreground/js/webui_command_extender.js b/ui/file_manager/file_manager/foreground/js/webui_command_extender.js
new file mode 100644
index 0000000000000000000000000000000000000000..5a9069a43183574288f57cceca93b30ab77f44fb
--- /dev/null
+++ b/ui/file_manager/file_manager/foreground/js/webui_command_extender.js
@@ -0,0 +1,20 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Sets 'hidden' property of a cr.ui.Command instance and dispatches
+ * 'hiddenChange' event manually so that associated cr.ui.MenuItem can handle
+ * the event.
+ * TODO(fukino): Remove this workaround when crbug.com/481941 is fixed.
+ *
+ * @param {boolean} value New value of hidden property.
+ */
+cr.ui.Command.prototype.setHidden = function(value) {
+  if (value === this.hidden)
+    return;
+
+  var oldValue = this.hidden;
+  this.hidden = value;
+  cr.dispatchPropertyChange(this, 'hidden', value, oldValue);
+};