Files.app: Make ProgressCenterItemGroup class to manage the states of items.

chrome/browser/chromeos/file_manager/file_manager_jstest.cc

 // Copyright 2013 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.
 
 #include <vector>
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
@@ skipping 21 matching lines @@
     FileManagerJsTest, NavigationListModelTest) {
   RunTest(base::FilePath(
       FILE_PATH_LITERAL("navigation_list_model_unittest.html")));
 }
 
 IN_PROC_BROWSER_TEST_F(
     FileManagerJsTest, FileOperationHandlerTest) {
   RunTest(base::FilePath(
       FILE_PATH_LITERAL("file_operation_handler_unittest.html")));
 }
+
+IN_PROC_BROWSER_TEST_F(
+    FileManagerJsTest, ProgressCenterItemGroupTest) {
+  RunTest(base::FilePath(
+      FILE_PATH_LITERAL("progress_center_item_group_unittest.html")));
+}