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

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

 // Copyright (c) 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.
 
 /**
  * Namespace for test related things.
  */
 var test = test || {};
 
 /**
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     var windowWrapper = background.appWindows[id];
     windows[id] = {
       innerWidth: windowWrapper.contentWindow.innerWidth,
       innerHeight: windowWrapper.contentWindow.innerHeight
     };
   }
   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;
+};
+
+/**
  * Gets a document in the Files.app's window, including iframes.
  *
  * @param {Window} contentWindow Window to be used.
  * @param {string=} opt_iframeQuery Query for the iframe.
  * @return {Document=} Returns the found document or undefined if not found.
  * @private
  */
 test.util.sync.getDocument_ = function(contentWindow, opt_iframeQuery) {
   if (opt_iframeQuery) {
     var iframe = contentWindow.document.querySelector(opt_iframeQuery);
@@ skipping 562 matching lines @@
       return false;
     } else {
       console.error('Invalid function name.');
       return false;
     }
   });
 };
 
 // Register the test utils.
 test.util.registerRemoteTestUtils();