This is a master bug for the UI to support the CSS Regions feature in the Web Inspector:
We had a discussion on IRC about the feature, so this is a short summary:
- The named flows should show as a separate folder "Flows" in the Resource Panel on the left. The folder will display under each frame similar to how "Images" and other resources work. The folder will not show if there are no flows in the document.
- Selecting the named flow will only display the elements that are part of the Flow.
- When you select an element that is part of the flow, the style panel should have a way to link back to the flow and the regions.
Also discussed was allowing you to pick between DOM Tree and Content for a flow. Selecting content would just show the flow text and possibly even let you edit it (copywriter mode) and apply live on the page.
CSS Regions were removed in Bug 174978.