How to make Firefox 39 display the page title of the active tab in the window title bar?

After upgrading to Firefox 39, the title of the page in the currently active tab is no longer displayed in the browser window's title bar. (In fact, there is no real title bar at all, even after turning on View -> Toolbars -> Menu Bar.) It is only displayed on the tab itself, where it gets cut off after a few words due to tab size.

How do I make Firefox display the title of the page in the active tab in the window title bar?

The ultimate goal being to be able to see (at least in the majority of cases) the full page title at a glance.

I'm willing to use an extension if necessary, but if possible, a solution that relies only on Firefox itself (no extensions, user scripts or anything like that) would be much preferred.

Running on Windows 8.1 Pro.

Answer

1. 
   

   Click on the Firefox 3-line Menu on the right.

   
   


2. 
   

   Select Customize at the bottom.

   
   


3. 
   

   Click on Title Bar in the bottom left corner.