+smut, maruel, I think we can probably update the image so that this is enabled along w/ kvm.

I've already got this implemented for non-swarmed bots, so I'm happy to either point to that or tweak the puppet config to run that logic on swarming bots.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3be4b416ed8a0c6cb5024ac90af8b978f706a018

commit 3be4b416ed8a0c6cb5024ac90af8b978f706a018
Author: Scott Graham <scottmg@chromium.org>
Date: Tue Sep 12 00:41:41 2017

fuchsia: Make swarming work (not enabled) and trybot results correct

Does a grabbag of things to get swarming tests working on trybots:
- Include support .py (runner script, testserver, sdk for bootfs) in
  data for runner so they're available on the bot
- Include filter files for now while the test binaries need test filters
- Use netcp to copy json results summary
- Make MB run the right command (i.e. out/Release/bin/run_blah) rather
  than trying to run a binary directly on the host
- Now that we can know when the process is done, shutdown of the target
  happens without a 3s delay.

This doesn't yet actually flip the bools of
can_use_on_swarming_builders: true for any binaries, as we need the
TUN/TAP device available on swarming bots, so that will happen in
follow ups.

This builds on testing and ssh setup work that jbudorick did in
https://chromium-review.googlesource.com/c/chromium/src/+/581429.

Bug:  761182 ,  734230 , 763992 
Change-Id: I9d2caf35658b7c8fae8c13e841cd464b225654e8
Reviewed-on: https://chromium-review.googlesource.com/645774
Commit-Queue: Scott Graham <scottmg@chromium.org>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501123}
[modify] https://crrev.com/3be4b416ed8a0c6cb5024ac90af8b978f706a018/build/config/fuchsia/rules.gni
[modify] https://crrev.com/3be4b416ed8a0c6cb5024ac90af8b978f706a018/build/fuchsia/exe_runner.py
[modify] https://crrev.com/3be4b416ed8a0c6cb5024ac90af8b978f706a018/build/fuchsia/runner_common.py
[modify] https://crrev.com/3be4b416ed8a0c6cb5024ac90af8b978f706a018/build/fuchsia/test_runner.py
[modify] https://crrev.com/3be4b416ed8a0c6cb5024ac90af8b978f706a018/testing/buildbot/filters/BUILD.gn
[modify] https://crrev.com/3be4b416ed8a0c6cb5024ac90af8b978f706a018/tools/mb/mb.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b80bdac0e830ce759d9a04d816b75a40ea85853e

commit b80bdac0e830ce759d9a04d816b75a40ea85853e
Author: Scott Graham <scottmg@chromium.org>
Date: Thu Sep 14 23:32:54 2017

fuchsia: Use minfs disk image for results extraction

SSH, virtio, hostfwd, tun/tap and many other options are either flaky,
require sudo, are excruciatingly slow, or some combination of these.

While writing to a disk and extracting the file on the host is a bit
silly, it's also fast and reliable, and doesn't require host
configuration or elevation.

Bug:  763992 , 761182 , 764567 
Change-Id: Ia66c54ba0879b9edb9725b074d489b58d7415948
Reviewed-on: https://chromium-review.googlesource.com/667867
Reviewed-by: Wez <wez@chromium.org>
Commit-Queue: Scott Graham <scottmg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502100}
[modify] https://crrev.com/b80bdac0e830ce759d9a04d816b75a40ea85853e/build/fuchsia/exe_runner.py
[modify] https://crrev.com/b80bdac0e830ce759d9a04d816b75a40ea85853e/build/fuchsia/runner_common.py
[modify] https://crrev.com/b80bdac0e830ce759d9a04d816b75a40ea85853e/build/fuchsia/test_runner.py

I think, after the above, we shouldn't need the TUN/TAP on swarming bots any more. (At least for now, until we have more complex networking requirements.) I think avoiding networking for this will likely be more robust in any case.

Sorry for the back and forth on this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4740a8431ee8dc3bbb5515c01a3d2954c8cd4c15

commit 4740a8431ee8dc3bbb5515c01a3d2954c8cd4c15
Author: Scott Graham <scottmg@chromium.org>
Date: Fri Sep 15 16:11:13 2017

fuchsia: Enable swarming for most test binaries

Following https://chromium-review.googlesource.com/667867 it should in
theory be ok to flip swarming on.

Still off for net_unittests for reasons yet tbd (see ps#2).

Bug:  763992 ,  761182 
Change-Id: I4c8838eeea34e64ecdfb50f770b8dadf5eaa1f03
Reviewed-on: https://chromium-review.googlesource.com/667501
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Scott Graham <scottmg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502269}
[modify] https://crrev.com/4740a8431ee8dc3bbb5515c01a3d2954c8cd4c15/testing/buildbot/chromium.fyi.json