UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36

Steps to reproduce the problem:
1) Run Chrome on Linux
2) Make a second chrome window (ctrl-n)
3) Make a third chrome window (ctrl-n)
3) Run the webgl aquarium in all 3 windows.
http://webglsamples.googlecode.com/hg/aquarium/aquarium.html

What is the expected behavior?
On a decent machine, it will run at ~60fps on all windows

What went wrong?
On 2 windows: 30ps
On 3 windows: 20fps

As mentioned here:
https://bugs.chromium.org/p/chromium/issues/detail?id=71439

Here's the issue: lets say you have N windows open, all of which are GPU acceleratred and both drawing at 60hz. Moreover, assume that they're not GPU bound.

In this case, the max frame rate achievable is 60/N on Linux and Windows [but not Mac].

The reason is because all these contexts flatten down to one GPU process. And, we block the GPU process' thread on present. So, even if the GPU process correctly interleaves thee windows rendering [which it probably won't], you get:
  Window1 processcommands for ~2ms
  Window1.Present for ~14ms
  Window2 processcommands for ~2ms
  Window2.Present for ~14ms
   ... and so on for every open window

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 58.0.3029.110  Channel: n/a
OS Version: 16.04 LTS
Flash Version: 

This behaviour is also happening with NWJS and is why I'm filing this issue, as it's detrimental to my multi-window app. If anyone can test this on other versions of Linux, I'd love to know your results!