This expands the whitespace and formats the braces to make it more readable. All of the breakpoints you add to the code will still work and it’s makes debugging production code that little bit easier.
In Chrome you can press the Pretty Print Button which is at the bottom of the script Windows. It does the same job as IE9. All of your breakpoint positions will be maintained.
If I have missed any options or overlooked any built in tools do let me know in the comments.