I ran into the same question. Does anyone has an answer for this?

I found the answer, which is fairly simple. Just need to add "A.viewMode", "A.editMode", and "A.helpMode" style in the style sheet. This is specific to the divRenderer that I am using. If you are using other renderer, it may be use different style. I have to go through the source code to figure this out. I wish it could be documented somewhere in the reference guide or used in the example layout.

This area of the portal is still kind of experimental in 2.0 that's why we were sort of hiding it. For the 2.2 release this will be a core feature and there will be documentation for it.