1263233 - verify all harnesses are running in e10s or not, fail the harness early if incorrect flags set

Status: NEW

(Testing :: General, defect)

Comment 1

[Ryan VanderMeulen [:RyanVM]]

I assume we'd also want to verify the opposite case (e10s disabled when we expect it to be).

Note to self: we'll presumably need to short-circuit whatever logic is added here in our "force e10s on for all test suites" Try patch or else hilarity will ensue.

Comment 2

[Andrew Halberstadt [:ahal]]

We can use `Services.appinfo.browserTabsRemoteAutostart` to determine whether e10s is enabled or not at runtime. This is better than checking the pref in case the pref changes in the future.

Would be nice to fit this into mozbase somewhere, though it would require marionette to run from python. Or maybe marionette-client could have an 'e10s_enabled' property on it or something.