E10s tree orange, preparing to land OOPP in mozilla-central

We are really close to having a green tree on Electrolysis. Here are the
known issues that remain:

* leak running mochitest-ipcplugins: bug 525792, bent
* hang running test_windowed_invalidate.html in mochitest-ipcplugins,
windows-only: bug 527876, bent
* print preview broken, windows-only: bug 527925, smaug

In addition, the following bugs block landing OOPP in mozilla-central:

* bug 519572 - ensure test frameworks expect subprocesses. As far as I'm
concerned, only the mochitest part of this needs to block landing in
mozilla-central (because we will only be testing OOPP via mochitests).
jgriffin has patch, pending review by ted.

* bug 523769 - prevent IPC messages during GC: bsmedberg, has patch pending
review mrbkap/jst

* Enable Talos for Electrolysis to make sure we haven't regressed any
IPC-off performance numbers... should be happening during the downtime right
now.

If you are a reviewer, I've cc'ed you on this message: please try to get to
these reviews ASAP: I'd like to try and land OOPP in mozilla-central early
next week.

--BDS