Add a mechanism to launch the utility process from the zygote on Linux.

Add a mechanism to launch the utility process from the zygote on Linux.

Allow the users of the utility process to specify whether the zygote
should be used on Linux. This will allow sandboxing the uses of the
utility process that don't do FS access.

This is the first step to get the utility process sandboxed
on Linux. Since most of the uses of the utility process
don't do file access, launching all of those from the zygote
will simplify sandboxing the one that does: extension
unpacking.

Subsequent CLs will port the uses of the utility process
that don't do file access to launch from the zygote.

BUG=93109
TEST=No functional changes yet, but test that nothing broke by
running browser_tests::ExtensionWebstorePrivateApiTest.* and also
logging into Chromium and installing an extension from the Web Store.


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=113914

[Jorge Lucangeli Obes, 2011-12-07 20:17:47]

Tread more carefully this time. First get the API in, and then port uses of the
utility process separately.

Thanks for the continuing reviews guys.

[jam, 2011-12-07 21:52:55]

lgtm

[Jorge Lucangeli Obes, 2011-12-08 23:43:16]

On 2011/12/07 21:52:55, John Abd-El-Malek wrote:
> lgtm

aa@: just checking whether this fell through the cracks. Thanks!

[Aaron Boodman, 2011-12-09 01:44:39]

lgtm

[commit-bot: I haz the power, 2011-12-09 19:04:10]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jorgelo@chromium.org/8849007/8001

[commit-bot: I haz the power, 2011-12-09 21:46:47]

Try job failure for 8849007-8001 (retry) on win_rel for step "ui_tests".
It's a second try, previously, step "ui_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2011-12-10 00:06:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jorgelo@chromium.org/8849007/8001

[commit-bot: I haz the power, 2011-12-10 01:30:57]

Change committed as 113914