Summary:
`debugger.html` contained a ton of hacky code that was needed to ensure we have a clean JS runtime every time a client RN app connects. That was needed because we used the page's global environment as runtime. Some time ago WebWorker support was added and now we run RN code inside an isolated WebWorker instance, and we can safely get rid of all these hacks.
This has a bunch of nice side-effects: debug reload works faster, `console.log`s are preserved, `debuggerWorker.js` selection doesn't change.
Made sure the debugging (breakpoints, etc.) still works as before.
Small demo
![](http://g.recordit.co/FPdVHLHPUW.gif)
Closes https://github.com/facebook/react-native/pull/5715
Reviewed By: svcscm
Differential Revision: D2906602
Pulled By: frantic
fb-gh-sync-id: 1a6ab9a5655d7c32ddd23619564e59c377b53a35