Your idea sounds reasonable. AFAIK, setting ozone true will default to drm platform and that would go wrong on the standard builders

The ozone builder on the main waterfall uses the following config:

dcheck_always_on = true
ffmpeg_branding = "ChromeOS"
goma_dir = "/b/c/cipd/goma"
is_component_build = false
is_debug = false
proprietary_codecs = true
symbol_level = 1
target_os = "chromeos"
use_goma = true
use_ozone = true

(e.g. https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_chromeos_ozone_rel_ng/builds/227351/steps/generate_build_files%20%28with%20patch%29/logs/stdio)

It doesn't list ozone_auto_platforms, or explicitly turns on any ozone platforms either. Not sure why that config would work OK for tests like views_unittests on that bot, but not work for views_mus_unittests etc. tests in the mojo fyi bot.

By default you'll get the following GN args where use_ozone=true and target_os="chromeos":

ozone_auto_platform=true
ozone_platform="headless"
ozone_platform_headless=true
ozone_platform_x11=true
ozone_platform_gbm=true

https://cs.chromium.org/chromium/src/ui/ozone/ozone.gni?q=ozone.gni&sq=package:chromium&dr&l=34

So it'll build headless, x11 and gbm but the tests will run as headless.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a17c267c6a457d280a75e8cd39aa39d6adcb58f3

commit a17c267c6a457d280a75e8cd39aa39d6adcb58f3
Author: msw <msw@chromium.org>
Date: Tue Aug 30 21:58:40 2016

Make the Mojo ChromiumOS fyi bot release+dcheck.

We used debug (component builds) to workaround  Issue 594674 .
Scott recently fixed mash browser tests for static builds with:
  https://codereview.chromium.org/2295433003/

Make the bot release again, but now with ozone+dchecks.
It's TBD if we need more args to make mash work with ozone:
 ozone_auto_platforms = false
 ozone_platform_x11 = true

BUG= 639882 , 642433 
TEST=Mojo ChromiumOS fyi bot does release+dcheck builds.
R=dpranke@chromium.org

Review-Url: https://codereview.chromium.org/2291013003
Cr-Commit-Position: refs/heads/master@{#415448}

[modify] https://crrev.com/a17c267c6a457d280a75e8cd39aa39d6adcb58f3/tools/mb/mb_config.pyl

Kyle will take a closer look.
We might be able to run these tests with --ozone-platform=x11
But that might require a fix for the tcmalloc  Issue 594674 
( or a workaround like Scott's https://codereview.chromium.org/2295433003/ )

So it looks like the tests pass when run with --ozone-platform=x11 but not with --ozone-platform=headless. The trybots use --ozone-platform=headless. So there are two separate things here:

1. Why don't the tests pass with --ozone-platform=headless? It looks like there is some problem command buffer IPC. Is this because Ozone platform only supports software rendering? Not super familiar with this part.
2. Can we run the tests using Ozone X11? Fixing the tcmalloc problem would make that relatively easy. Otherwise could something be done similar to browser tests? I also have a patch to run Ozone X11 tests in xvfb that would need to land first but that's basically ready.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6ff0ca0258695fad627c4cd7942e4f946ff9f910

commit 6ff0ca0258695fad627c4cd7942e4f946ff9f910
Author: kylechar <kylechar@chromium.org>
Date: Mon Nov 07 16:39:34 2016

Add mustash tests to Ozone CrOS trybot.

Run the following tests on linux_chromium_chromeos_ozone_rel_ng:
1. mus_demo_unittests
2. views_mus_interactive_ui_tests
3. views_mus_unittests

BUG= 642433 , 611473 

Review-Url: https://codereview.chromium.org/2478633003
Cr-Commit-Position: refs/heads/master@{#430294}

[modify] https://crrev.com/6ff0ca0258695fad627c4cd7942e4f946ff9f910/testing/buildbot/chromium.chromiumos.json

The tests are now running as part of CQ on linux_chromium_chromeos_ozone_rel_ng.