Create ListContainer and SpinnerController class.

ui/file_manager/file_manager/foreground/js/spinner_controller.js

Index: ui/file_manager/file_manager/foreground/js/spinner_controller.js
diff --git a/ui/file_manager/file_manager/foreground/js/spinner_controller.js b/ui/file_manager/file_manager/foreground/js/spinner_controller.js
new file mode 100644
index 0000000000000000000000000000000000000000..60e953d09b722a7a35753e2c3f68e77fc28be5a4
--- /dev/null
+++ b/ui/file_manager/file_manager/foreground/js/spinner_controller.js
@@ -0,0 +1,67 @@
+// Copyright 2014 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.
+
+/**
+ * Controller for spinner.
+ * @param {!HTMLElement} element
+ * @param {!DirectoryModel} directoryModel
+ * @constructor
+ */
+function SpinnerController(element, directoryModel) {
+  /**
+   * The container element of the file list.
+   * @type {!HTMLElement}
+   * @const
+   * @private
+   */
+  this.element_ = element;
+
+  /**
+   * Directory model.
+   * @type {!DirectoryModel}
+   * @const
+   * @private
+   */
+  this.directoryModel_ = directoryModel;
+
+  /**
+   * @type {number}
+   * @private
+   */
+  this.timeoutId_ = 0;
+}
+
+/**
+ * Shows the spinner.
+ */
+SpinnerController.prototype.show = function() {
+  if (!this.directoryModel_.isScanning())
+    return;
+  this.element_.hidden = false;
+  clearTimeout(this.timeoutId_);
+  this.timeoutId_ = 0;
+};
+
+/**
+ * Hides the spinner.
+ */
+SpinnerController.prototype.hide = function() {
+  if (this.directoryModel_.isScanning() &&
+      this.directoryModel_.getFileList().length == 0) {
+    return;
+  }
+  this.element_.hidden = true;
+  clearTimeout(this.timeoutId_);
+  this.timeoutId_ = 0;
+};
+
+/**
+ * Shows the spinner after 500ms.
+ */
+SpinnerController.prototype.showLater = function() {
+  if (!this.element_.hidden)
+    return;
+  clearTimeout(this.timeoutId_);
+  this.timeoutId_ = setTimeout(this.show.bind(this), 500);
+};