Fixing exit on 'X' icon in Photo Editor

chrome/browser/resources/file_manager/js/mock_chrome.js

Index: chrome/browser/resources/file_manager/js/mock_chrome.js
diff --git a/chrome/browser/resources/file_manager/js/mock_chrome.js b/chrome/browser/resources/file_manager/js/mock_chrome.js
index d5c71bdfcc079f915f5aabc997b551b85a30e4f3..403a2f81b1cb7532bb9d0223193355e46fc1951c 100644
--- a/chrome/browser/resources/file_manager/js/mock_chrome.js
+++ b/chrome/browser/resources/file_manager/js/mock_chrome.js
@@ -59,6 +59,21 @@ chrome.fileBrowserPrivate = {
   },
 
   /**
+   * File system change notification.
+   */
+  onFileChanged: {
+    callbacks: [],
+    addListener: function(cb) { this.callbacks.push(cb) }
+  },
+
+  /**
+   * File watchers.
+   */
+  addFileWatch: function(path, callback) { callback(true) },
+
+  removeFileWatch: function(path, callback) { callback(true) },
+
+  /**
    * Returns common tasks for a given list of files.
    */
   getFileTasks: function(urlList, callback) {