Updates chrome.tab.highlight definition to reflect that the callback is optional.
@@ -3047,8 +3047,8 @@ chrome.tabs.HighlightInfo;
/**
* @see https://developer.chrome.com/extensions/tabs#method-highlight
* @param {!chrome.tabs.HighlightInfo} highlightInfo
- * @param {function(!ChromeWindow): void} callback Callback function invoked
- * with each appropriate Window.
+ * @param {function(!ChromeWindow): void=} callback Callback function invoked
+ * for each window whose tabs were highlighted.
* @return {undefined}
*/
chrome.tabs.highlight = function(highlightInfo, callback) {};
