What steps will reproduce the problem?
(1) Start a component update with the command line argument --component-updater=fast-update
(2) navigate to chrome://components and observe the update progress.
(3) After CRLSet has updated but while other components are still updating, hit "Check for update" button for CRLset.

What is the expected result?
Status should change to "Status - Component not updated"

What happens instead?
Status changes to "Status - Checking for status…"

The reason it is doing this is that the update client code returns an error while a component is asked to update while it is part of an update task already.

if (IsUpdating(id)) {
    std::move(callback).Run(Error::UPDATE_IN_PROGRESS);
    return;
}

The UI is not handling this error.