Added one line to new test-adb-pure
Added infrastructure to restart ADB
Restart ADB instead of calling exit() and crashing

There were code paths that could possibly hit a call to exit. Whenever
this function is called, Firefox crashes.
To fix this, whenever ADB wants to fatally exit, it will callback to JS.
EventedChromeWorker auto-installs a listener for restarting (like the
listener for console logging).