UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.10 Safari/537.36

Steps to reproduce the problem:
1. Go to dev tools, Network pane
2. Resize waterfall by dragging its column left edge.
3. Resize the window.

What is the expected behavior?
We expect the left part (everything left of the waterfall) to remain the same size, and only the waterfall column to change size.

What went wrong?
All the columns get resized instead, resulting in unreadable content (columns too small).

Did this work before? No 

Chrome version: 60.0.3112.10  Channel: dev
OS Version: 10.0
Flash Version: 

In the network panel, all the columns except the waterfall should stay the same size when resizing. Resizing them makes no sense because if they are too small, their content won't be readable, and if they are too wide, it's wasted space that could be used for the waterfall.
Especially if you spend the time to resize the columns the way you want, you definitely want them to stay the same width when you resize the window (to a smaller size), and only have the waterfall width adjusted.