I took a quick look at this, and I can't figure out how to hold cr-view-manager from the sources. There aren't really any docs, and only one example of use-in-anger.
It looks like perhaps this is just a convenience element to provide the switchView() function, and everything else has to be done by the enclosing elements and logic?

A very minimal new example is at https://cs.chromium.org/chromium/src/chrome/browser/resources/md_user_manager/user_manager_pages.html. See the CL at https://chromium-review.googlesource.com/c/chromium/src/+/1029952/. Does that help?

Linked to the wrong CL. Here is the correct link https://chromium-review.googlesource.com/c/chromium/src/+/1327420.

> It looks like perhaps this is just a convenience element to provide the switchView() function, and everything else has to be done by the enclosing elements and logic?

Also, cr-view-manager takes care of the transition animations, as well as properly styling the active and non-active views (where by "styling" I mean hiding/showing).

The enclosing element's responsibility is to simply call switchView(viewId) as necessary, where |viewId| should match the ID of an element that has slot="view".

I agree that the cr-view-manager documentation needs improvement (it is basically non-existent).

The other fairly convenient functionality that it provides is to fire the following 4 events on the views that are entered/exited.
view-enter-start (start of animation)
view-enter-finish (end of animation)
view-exit-start
view-exit-finish

These can be very useful, for example if you need to focus a certain UI element once a view becomes active.

Thanks, I can now hold cr-view-manager right. I started looking into replacing the paper-tabs with cr-toolbar, but that seems like overkill. Can you recommend (and point to) some way for making the "one from closed set of views" selection?

> I started looking into replacing the paper-tabs with cr-toolbar, but that seems like overkill. 

cr-toolbar is not equivalent to paper-tabs

> Can you recommend (and point to) some way for making the "one from closed set of views" selection?

I don' think we have our own "cr" equivalent element for this. iron-selector [1] could be an alternative to paper-tabs, but this is still a 3rd party dependency, so probably not worth migrating to.

[1] https://cs.chromium.org/search/?q=%22%3Ciron-selector%22+-file:third_party+-file:infra+-file:out/Debug+-file:out/chromium-android/Debug+-file:out/android-Debug+-file:src/v8+-file:src/native_client-sdk+-file:src/out/&type=cs