See: https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=services_unittests&tests=NetworkContextTest.CloseIdleConnections

Example test failure: 
https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8929796574639644480/+/steps/services_unittests__with_patch_/0/logs/NetworkContextTest.CloseIdleConnections/0

I think this is because there's a race between RemoveConnectJob on the IO thread and the main thread runloop quitting. Could you please disable or fix this test, thanks!