M8 and M9 Check-in Rules

[Mike Schroepfer]

Hey Folks,

Below is meant to be a simplified tree check-in rule statement to be
linked from the tinderbox pages. Thanks to Phil R for both bringing it
up and writing it for us :-).

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From the reopening after M8 until two weeks before M9, check-ins for
bugs marked blocking1.9+ or blocking-firefox3+ do not require
approval1.9+, check-ins for all other bugs (including browser/ and
toolkit/) which affect Firefox require approval1.9+ from the area drivers.

For the last two weeks before M9, all check-ins affecting Firefox
require approval1.9+ from the end-game drivers.

At all times, check-ins which do not affect Firefox only have their
normal review requirements, as long as the tree is open.