Enable VizDisplayCompositor on CrOS.

1. Enable feature on CrOS. We are preparing for an M77 launch. Rollout
   will still be finch controlled but we need to enable the feature in
   code for Chrome OS infra to start running with it.
2. Flip viz_* tests to be non_viz_* since tests will now run with
   VizDisplayCompositor enabled by default.
3. Remove viz_content_unittests from FYI bots since the same test is
   already in CQ.

Note that the VizDisplayCompositor feature shifts a significant amount
of work from the browser to GPU process, which has both memory and CPU
time implications. Once this change is picked up in Chrome OS and hits
the perf bots it will likely trigger numerous alerts. Please assign bugs
to kylechar@chromium.org so I can investigate if it's a real regression
or just shifting work between processes.

Bug: 732805
Change-Id: I628aba5efcb0d1c8499753695e4c915aa5344044
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1708415
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#679283}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: bd5d5fe84c358e1edbfeab03dbb475423d34d29c
6 files changed