Add unit tests for utility functions of FileOperationManager.

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 67b70011a56ccc4ba61594c431ba9bb4bf9ef9a3..db92a316391f7c91600a7b55917888c6c3142d1f 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_jstest.cc
@@ -55,3 +55,8 @@ IN_PROC_BROWSER_TEST_F(
     FileManagerJsTest, MetadataCacheTest) {
   RunTest(base::FilePath(FILE_PATH_LITERAL("metadata_cache_unittest.html")));
 }
+
+IN_PROC_BROWSER_TEST_F(FileManagerJsTest, FileOperationManagerTest) {
+  RunTest(base::FilePath(
+      FILE_PATH_LITERAL("file_operation_manager_unittest.html")));
+}