Admin UI crashes Chrome DevTools

[jesstelford]

This seems to happen randomly in a number of places - when you have Chrome's DevTools open, and try to do some things in the Admin UI (click a link, create an item, etc), DevTools will crash, and then the entire Chrome tab will become unresponsive while chewing up CPU 📈

One reproducible case is on Chrome OSX 69.0.3497.100, and the code in #433;

• Create a list with a field containing a unique constraint
• Create an item in that list with a unique field value
• Create a second item in that list with a different unique field value
• Edit the second item
• Open Chrome DevTools, and visit the Network tab
• Change the value of the unique field to match the value of the first item created (ie; violating the unique constraint)
• Watch it burn 🔥
  • Notice the completed network request is shown, but when you click on it, it doesn't show any "preview" data.
  • Notice the Admin UI is now unresponsive.
  • Notice you cannot close the tab.
  • Notice yourself questioning all your life choices.