A similar question has been asked before, but had no traction. Clearly, it is possible but it is by no means clear how to do it in our own non-tabris Android app.
The best documentation we have on the matter is this commit, but I tried V8.setFlags("--expose-debug-as=Debug"); as well as V8.setFlags("--expose-debug-as=" + DebugHandler.DEBUG_OBJECT_NAME); but no debuggable app appeared in chrome developer tools.
I even tried in combo with enabling Stetho and in that case I was able to debug the app, but there was no javascript source to debug. I believe that I'm close but missing one small crucial nugget.
If the question is still relevant - I have created j2v8-debugger library.
It allows debugging
J2V8using Chrome DevTools.It indeed uses Stetho lib for communication with Chrome DevTools.
Also it's uses DebugHandler for accessing V8 debug information.
Basic features like setting/removing breakpoints, step into, step out and step over, variables inspection, etc. are implemented.
Hope it could be helpful.