Leak fix in tabs-main.ts

[dfriederich]

The disconnect from the signal was not passing the this reference as it was used in the connect, hence the disconnect failed to find the handler.

When developing a theia based app we run into leaks due to TabsMainImpl keeping our custom control
in memory even when it was closed. The leak was through the controls title, through TabsMainImpl.
This PR fixes the main issue, which was leaking every control for us.

However the TabsMainImpl still is not optimal as it only releases references when it rebuilds its model,
and that does not happen when closing a tab.

[msujew]

Thanks looks good to me 👍

However the TabsMainImpl still is not optimal as it only releases references when it rebuilds its model, and that does not happen when closing a tab.

I plan to refactor the code that handles the tab API and the whole editor manager eventually anyway. This will likely be fixed by that change.

[dfriederich]

I plan to refactor the code that handles the tab API and the whole editor manager eventually anyway.
This will likely be fixed by that change.

The leak is quite unfortunate IMHO, wonder how bad it would be to recompute the model for any tab removal?
would at least fix the leak for me. I will create an issue to track that it currently leaks.

[martin-fleck-at]

I'm also interested in this, so thank you @dfriederich for creating #14203.
@msujew Do you have any approximate timeline on this?