Linux linux_web_engine_tests is flaky #180940
Description
Some recent failed runs:
https://ci.chromium.org/ui/p/flutter/builders/prod/Linux%20linux_web_engine_tests/5466/infra
https://ci.chromium.org/ui/p/flutter/builders/prod/Linux%20linux_web_engine_tests/5473/infra
The failing test is in style_manager_test.dart. The failure log is:
00:13 +441 ~28 -1: view_embedder/style_manager_test.dart: StyleManager attachGlobalStyles hides the outline when focused [E]
Expected: 'rgb(0, 0, 0) 0px'
Actual: 'rgb(0, 0, 0) 3px'
Which: is different.
Expected: ... (0, 0, 0) 0px
Actual: ... (0, 0, 0) 3px
^
Differ at offset 13
On my Linux cloudtop, the test is flaky, although it will pass for many test runs in a row and then fail for many runs in a row.