The test "PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0" fails when run after other PermissionContextBaseTests tests, which happens naturally when running unit_tests. It passes when the try bots re-run it standalone, as seen on the flakiness dashboard.

$ ./out_linux/rel/unit_tests --gtest_filter=PermissionContextBaseTestsInstance/PermissionContextBaseTests.TestDismissVariations/0:PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0
IMPORTANT DEBUGGING NOTE: batches of tests are run inside their
own process. For debugging a test inside a debugger, use the
--gtest_filter=<your_test_name> flag along with
--single-process-tests.
Using sharding settings from environment. This is shard 0/1
Using 1 parallel jobs.
Note: Google Test filter = PermissionContextBaseTestsInstance/PermissionContextBaseTests.TestDismissVariations/0:PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0
[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from PermissionContextBaseTestsInstance/PermissionContextBaseTests
[ RUN      ] PermissionContextBaseTestsInstance/PermissionContextBaseTests.TestDismissVariations/0
[       OK ] PermissionContextBaseTestsInstance/PermissionContextBaseTests.TestDismissVariations/0 (1225 ms)
[ RUN      ] PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0
../../chrome/browser/permissions/permission_context_base_unittest.cc:388: Failure
      Expected: PermissionStatusSource::MULTIPLE_DISMISSALS
      Which is: 4-byte object <03-00 00-00>
To be equal to: result.source
      Which is: 4-byte object <00-00 00-00>
../../chrome/browser/permissions/permission_context_base_unittest.cc:389: Failure
      Expected: CONTENT_SETTING_BLOCK
      Which is: 2
To be equal to: result.content_setting
      Which is: 3
../../base/test/histogram_tester.cc:178: Failure
      Expected: expected_count
      Which is: 1
To be equal to: actual_count
      Which is: 0
Histogram "Permissions.AutoBlocker.EmbargoStatus" does not have the right number of samples (1) in the expected bucket (2). It has (0).
../../chrome/browser/permissions/permission_context_base_unittest.cc:420: Failure
      Expected: CONTENT_SETTING_BLOCK
      Which is: 2
To be equal to: result.content_setting
      Which is: 3
../../chrome/browser/permissions/permission_context_base_unittest.cc:421: Failure
      Expected: PermissionStatusSource::MULTIPLE_DISMISSALS
      Which is: 4-byte object <03-00 00-00>
To be equal to: result.source
      Which is: 4-byte object <00-00 00-00>
../../base/test/histogram_tester.cc:178: Failure
      Expected: expected_count
      Which is: 1
To be equal to: actual_count
      Which is: 0
Histogram "Permissions.AutoBlocker.EmbargoPromptSuppression" does not have the right number of samples (1) in the expected bucket (2). It has (0).
../../chrome/browser/permissions/permission_context_base_unittest.cc:897: Failure
      Expected: CONTENT_SETTING_BLOCK
      Which is: 2
To be equal to: result.content_setting
      Which is: 3
../../chrome/browser/permissions/permission_context_base_unittest.cc:898: Failure
      Expected: PermissionStatusSource::MULTIPLE_DISMISSALS
      Which is: 4-byte object <03-00 00-00>
To be equal to: result.source
      Which is: 4-byte object <00-00 00-00>
../../chrome/browser/permissions/permission_context_base_unittest.cc:903: Failure
      Expected: CONTENT_SETTING_BLOCK
      Which is: 2
To be equal to: result.content_setting
      Which is: 3
../../chrome/browser/permissions/permission_context_base_unittest.cc:904: Failure
      Expected: PermissionStatusSource::MULTIPLE_DISMISSALS
      Which is: 4-byte object <03-00 00-00>
To be equal to: result.source
      Which is: 4-byte object <00-00 00-00>
[  FAILED  ] PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0, where GetParam() = 4-byte object <00-00 00-00> (23 ms)
[----------] 2 tests from PermissionContextBaseTestsInstance/PermissionContextBaseTests (1249 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (1249 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0, where GetParam() = 4-byte object <00-00 00-00>

 1 FAILED TEST
[88174:88177:0817/223649.762430:10200033260548:ERROR:kill_posix.cc(83)] Unable to terminate process group 88178: No such process (3)
[1/2] PermissionContextBaseTestsInstance/PermissionContextBaseTests.TestDismissVariations/0 (1225 ms)
[2/2] PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0 (23 ms)
1 test failed:
    PermissionContextBaseTestsInstance/PermissionContextBaseTests.PushMessagingEmbargoEmbargoesNotifications/0 (../../chrome/browser/permissions/permission_context_base_unittest.cc:841)
Tests took 2 seconds.
e