Files.app: Add a unit test of ProgressCenterHandler class.

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 f3252d985b4f4ad0488b322424ebc425d96d5833..e82f7c50fac4e82d904bc078b9635aae19e25346 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
@@ -33,3 +33,9 @@ IN_PROC_BROWSER_TEST_F(
   RunTest(base::FilePath(
       FILE_PATH_LITERAL("navigation_list_model_unittest.html")));
 }
+
+IN_PROC_BROWSER_TEST_F(
+    FileManagerJsTest, ProgressCenterHandlerTest) {
+  RunTest(base::FilePath(
+      FILE_PATH_LITERAL("progress_center_handler_unittest.html")));
+}