Web+ should not start resizing tabs until mouse is withdrawn

[bitigchi]

Web+ starts calculating tab length right after closing a tab.

Steps:

1. Open a few tabs, preferably fill up the whole bar
2. Move mouse to the first tab, and close the tab

Expectation:

1. Web+ should keep the tabs at the previous size to allow easier closing of other tabs

Actual result:

1. Tabs immediately gets resized across the tab bar, so one has to adjust the mouse position to close the other tabs