We concatenate JSMs together so we use less compartments and therefore
less memory. This is intended to be a temporary hack until the overhead
of compartments is less.
This also includes a lot of revamped Firefox Health Report features. The
payload format has changed. There is now robust service shutdown logic.
There are more prefs to control behavior. It's almost a rewritten
service.
Dave Townsend
Gregory Szorc
Richard Newman