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

chrome/browser/chromeos/file_manager/file_manager_jstest.cc

Index: chrome/browser/chromeos/file_manager/file_manager_jstest.cc
diff --git a/chrome/browser/chromeos/file_manager/file_manager_jstest.cc b/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
index f028a491bee0bdfe6d088ff76ded36ea7f1c409c..3409ffe619ba7234b3f156fa9453d89c97cf1005 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
@@ -39,3 +39,9 @@ IN_PROC_BROWSER_TEST_F(
   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")));
+}