UserAgent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.84 Safari/537.36

Steps to reproduce the problem:
1.  $(window).bind('beforeunload', function (event) { return "blah blah"; });
2. 
3. 

What is the expected behavior?
has to show custom message as well

What went wrong?
custom message is missing

Did this work before? Yes 51.0.2704.63

Chrome version: 51.0.2704.84  Channel: n/a
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: Shockwave Flash 21.0 r0