Chrome Version       : 58.0.3029.110

What steps will reproduce the problem?
1. Clone https://github.com/aslushnikov/ftree
2. cd ftree; git checkout 5ee71c31cf45c9bc3ce23e414cae7ac8f87a235e
3. python -m SimpleHTTPServer 8080
4. navigate to localhost:8080
5. in top-right corner, select 'japanese imperial family'

Actual: chrome gets stuck, it's impossible to open devtools and figure what's going on
Expected: it is possible to open devtools and figure the issue