Revert "Merge views_mus_unittests and views_unittests"

This reverts commit bddf4c6eeb6cacaeb012208c84cb88cc9dca3458.

Reason for revert: linux-chromeos-dbg, Linux Chromium OS ASan LSan Tests (1), and Linux ChromiumOS MSan Tests bots are burning in the "all tests are failing" way. This change touches CrOS in a very suspicious way.

Original change's description:
> Merge views_mus_unittests and views_unittests
>
> - Allow testing DesktopNativeWidgetAura on Chrome OS by doing necessary
>   Mus setup.
> - To accommodate Chrome OS, tests must specify that they will be testing
>   desktop widgets before SetUp (for tests that inherit from
>   ViewsTestBase). On Chrome OS, these are the tests that provide Mus
>   coverage.
> - Command line flags are ignored, so views_unittests will perform the
>   same tests with and without --enable-features=SingleProcessMash
> - Enable some test suites on Chrome OS, such as
>   desktop_native_widget_aura_unittest.cc, and some individual tests.
>
> Bug: 911784
> Change-Id: Ic3acd21770f07fb8298a172dc556b3fa036d6791
> Reviewed-on: https://chromium-review.googlesource.com/c/1378666
> Commit-Queue: Evan Stade <[email protected]>
> Reviewed-by: Tom Sepez <[email protected]>
> Reviewed-by: Scott Violet <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#618646}

[email protected],[email protected],[email protected]

# Not skipping CQ checks because original CL landed > 1 day ago.

NOPRESUBMIT=true

Bug: 911784
Change-Id: Ia2d3ee0931565c6e41c1ded868a2edd0e873870a
Reviewed-on: https://chromium-review.googlesource.com/c/1390427
Commit-Queue: Avi Drissman <[email protected]>
Reviewed-by: Avi Drissman <[email protected]>
Cr-Commit-Position: refs/heads/master@{#618842}
diff --git a/BUILD.gn b/BUILD.gn
index 6e48a19..61b8940 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -653,6 +653,8 @@
       "//mash:all",
       "//media/mojo/services:media_service_unittests",
       "//mojo",
+      "//ui/views/mus:views_mus_interactive_ui_tests",
+      "//ui/views/mus:views_mus_unittests",
     ]
 
     # crbug.com/676055: media_service_unittests fails to link under Windows