function detectPrivateMode()

in tools/CCPConnectivityTestTools/scripts/detectRTC.js [227:299]
44 lines of code
14 McCabe index (conditional complexity)

    function detectPrivateMode(callback) {
        var isPrivate;

        try {

            if (window.webkitRequestFileSystem) {
                window.webkitRequestFileSystem(
                    window.TEMPORARY, 1,
                    function() {
                        isPrivate = false;
                    },
                    function(e) {
                        isPrivate = true;
                    }
                );
            } else if (window.indexedDB && /Firefox/.test(window.navigator.userAgent)) {
                var db;
                try {
                    db = window.indexedDB.open('test');
                    db.onerror = function() {
                        return true;
                    };
                } catch (e) {
                    isPrivate = true;
                }

                if (typeof isPrivate === 'undefined') {
                    retry(
                        function isDone() {
                            return db.readyState === 'done' ? true : false;
                        },
                        function next(isTimeout) {
                            if (!isTimeout) {
                                isPrivate = db.result ? false : true;
                            }
                        }
                    );
                }
            } else if (isIE10OrLater(window.navigator.userAgent)) {
                isPrivate = false;
                try {
                    if (!window.indexedDB) {
                        isPrivate = true;
                    }
                } catch (e) {
                    isPrivate = true;
                }
            } else if (window.localStorage && /Safari/.test(window.navigator.userAgent)) {
                try {
                    window.localStorage.setItem('test', 1);
                } catch (e) {
                    isPrivate = true;
                }

                if (typeof isPrivate === 'undefined') {
                    isPrivate = false;
                    window.localStorage.removeItem('test');
                }
            }

        } catch (e) {
            isPrivate = false;
        }

        retry(
            function isDone() {
                return typeof isPrivate !== 'undefined' ? true : false;
            },
            function next(isTimeout) {
                callback(isPrivate);
            }
        );
    }