1] Component Name: Service

2] Parent Component (e.g. Blink, UI>Browser, etc...): Internals>Preferences

(There's no widely used Preferences component already and this naming scheme are followed by other services, such as Internals>Network>Service.)

3] Description of Component: A Mojo service for storing preferences that can be accessed by other services.

4] Admin/ Owner: tibell

5] Please specify what triage practices will be followed for the component
(i.e. what team will do it and how frequently).

The preferences servicification team will triage bugs as they come in (we don't expect that many).

(Several times in the past months we felt a lack of this component when creating/triaging bugs, so hence we think there's a need for it.)