extensions/pdfViewer/pdf/web/viewer.js
function preferencesReset() {
    return this.initializedPromise.then(function() {
      this.prefs = Object.create(DEFAULT_PREFERENCES);
      return this._writeToStorage(DEFAULT_PREFERENCES);
    }.bind(this));
  }
function preferencesReset() {
    return this.initializedPromise.then(function() {
      this.prefs = Object.create(DEFAULT_PREFERENCES);
      return this._writeToStorage(DEFAULT_PREFERENCES);
    }.bind(this));
  }
function preferencesReset ( ) { return this . initializedPromise . then ( function ( ) { this . prefs = Object . create ( DEFAULT_PREFERENCES ) ; return this . _writeToStorage ( DEFAULT_PREFERENCES ) ; } . bind ( this ) ) ; }
Reset the preferences to their default values and update storage.
@return {Promise} A promise that is resolved when the preference values
have been reset.
Reset the preferences to their default values and update storage .