Chrome Version: 58.0.2995.0 (Developer Build) (64-bit)
OS: Linux

What steps will reproduce the problem?
(1) Create a snippet with this:

var x = function () {

    
};

(2) Run pretty-print one time and you'll see this:

var x = function() {
};


(3) Run pretty-print a second time and you'll see this:

var x = function() {};


What is the expected result? Running pretty-print a second time should have no effect.