1938448 - [meta] Package newtab as a built-in addon

Status: NEW

(Firefox :: New Tab Page, task)

Description

[Mike Conley (:mconley) (:⚙️)]

Bug 1938445 is a larger set of work that ensures that all of the infrastructure is in place that will allow newtab to ship fixes, updates and experiments via addon updates.

This metabug is more precise - it's for bugs to package newtab as a built-in addon. This will require us to:

1. Move most (but not all) of newtab into browser/extensions/newtab
2. Provide a manifest.json for the addon
3. Update moz.build to install the built-in addon
4. Add any special AddonManager invocations to BrowserGlue for built-in addons. Something like bug 1938155 might be inspiration.
5. Add an api.js script that lets us map resource://activity-stream to the addon data path.

Ideally, (3), (4) and (5) can be put behind some kind of build-flag so that the rest of New Tab development is not disrupted by our movements here.