DOMWrapperWorldTest.Basic will consistently fail when run after other tests. For example:
out/Debug/webkit_unit_tests --single-process-tests --test-launcher-total-shards=1 --gtest_filter=ActivityLoggerTest.RequestResource:DOMWrapperWorldTest.Basic

../../third_party/blink/renderer/bindings/core/v8/dom_wrapper_world_test.cc:94: Failure
Value of: DOMWrapperWorld::NonMainWorldsExistInMainThread()
  Actual: true
Expected: false
Stack trace:
0 base::debug::StackTrace::StackTrace() + 28
1 StackTraceGetter::CurrentStackTrace(int, int) + 90
2 testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop(int) + 71
3 testing::internal::AssertHelper::operator=(testing::Message const&) const + 139
4 blink::(anonymous namespace)::DOMWrapperWorldTest_Basic_Test::TestBody() + 1015


This may be the root cause of the flakiness reported in  https://crbug.com/774364 . I think DOMWrapperWorld tests need to ensure the state is clean in their setup, or we need other tests (e.g., ActivityLoggerTest) to clear DOMWrapperWorld-related state when they finish.

tzik, can you investigate this flaky test issue?