bug#52232: 29.0.50; Can scroll horizontally with pixel-scroll-precision-mode

[Yuan Fu]

> 
> Then the problem is not in pixel-scroll-precision-mode, I think.
> 
> I did some work on NS mouse wheel handling a few days ago.  Could you
> update and try again?  Thanks.

Thank you for following up on this. I pulled the master and tried again, and 
the situation has not changed. I have no knowledge of the nsterm to investigate 
by myself, sorry :-( If there is anything that I can do to help, please let me 
know.

I’ll ask if my friends that uses a Mac can try master and see if they have the 
same problem.

Yuan