The ContentSuggestionsService::Observer interface currently has these two main functions for updates:
 - void OnNewSuggestions(Category category);
 - void OnCategoryStatusChanged(Category category,
                                CategoryStatus new_status);

Status and suggestions for a category can change at the same time and they can also change independently. Say, if a status change comes to the observer (e.g., UI), it is not clear whether newSuggestions will also arrive immediately afterwards or not. It is not even clear if the status change comes first or the newSuggestions notification comes first.

This adds unnecessary complexity and brittleness to the implementation of the observers.

We should fix it.

Maybe by adding a third function 
 - void onCategoryStatusAndSuggestionsChanged(Category category, CategoryStatus new_status)?

Nicolas, Gauthier, do you have a better proposal?