I still don't get it. What problem they're trying to avoid?
It's exactly the same if two extensions would currently try to manipulate the page by adding a frame (or, worse, a <div> with non-isolated UI) to the same location.
The only difference is, with out-of-page widgets (e.g. overlay regions or popouts), they won't be visible in the page's DOM.
It's exactly the same if two extensions would currently try to manipulate the page by adding a frame (or, worse, a <div> with non-isolated UI) to the same location.
The only difference is, with out-of-page widgets (e.g. overlay regions or popouts), they won't be visible in the page's DOM.