Revert of [AudioPlayer] Add test for opening another file from Files.app

chrome/browser/resources/file_manager/background/js/test_util.js

Index: chrome/browser/resources/file_manager/background/js/test_util.js
diff --git a/chrome/browser/resources/file_manager/background/js/test_util.js b/chrome/browser/resources/file_manager/background/js/test_util.js
index e69b9d7d26fcc122437b62725621e60d4a95aca9..75d45cb73b6e17e4d9fa522d21963517279c8364 100644
--- a/chrome/browser/resources/file_manager/background/js/test_util.js
+++ b/chrome/browser/resources/file_manager/background/js/test_util.js
@@ -69,21 +69,6 @@
     };
   }
   return windows;
-};
-
-/**
- * Closes the specified window.
- *
- * @param {string} appId AppId of window to be closed.
- * @return {boolean} Result: True if success, false otherwise.
- */
-test.util.sync.closeWindow = function(appId) {
-  if (appId in background.appWindows &&
-      background.appWindows[appId].contentWindow) {
-    background.appWindows[appId].close();
-    return true;
-  }
-  return false;
 };
 
 /**