Chrome version: (copy from chrome://version) 67.0.3383.0 (Official Build) dev (64-bit)
OS: Chrome

Repro steps:
1. install crostini VM Per go/crostini-instructions
2. sudo apt-get update
3. sudo apt-get upgrade  
4. Then install octave: sudo apt-get install octave-communications octave-statistics octave-symbolic  
[can omit the accessory packages octave-* probably, however "less" is needed actually and is not a dependency of octave oddly, but that's not the issue here

5. open octave and do the simple demo:
x = -10:0.1:10; # Create an evenly-spaced vector from -10..10
y = sin (x);    # y is also a vector
plot (x, y);
title ("Simple 2-D Plot");
xlabel ("x");
ylabel ("sin (x)");


Expected: 
Note this should open up a plot window with sin(x) in it.

Actual: 
The plot does not open and octave hangs