function maybeCallback()
        {
            if (scriptsLeft)
                return;

            var result = [];
            for (var i = 0; i < scripts.length; ++i)
                result = result.concat(results[scripts[i].scriptId]);
            callback(result);
        }
@param {string} query
@param {boolean} caseSensitive
@param {boolean} isRegex
@param {function(!Array.<!WebInspector.ContentProvider.SearchMatch>)} callback