Only applicable to iOS 8+. Checks if metrics setting has been declared to be offered in app, if not: adds ℹ️ action to open the app's Settings.app section.
Fixes#1519. Squash of #1529.
The singleton `MGLAccountManager` wants to be the sole arbiter of the access token, but each instance of `mbgl::Map` (`mbgl::DefaultFileSource` in #1607) has its own copy of the access token. Now `MGLMapView` observes for changes to the `MGLAccountManager`’s access token and synchronizes `mbgl::Map` with it.
`-pauseMetricsCollection` and `-resumeMetricsCollection` were originally introduced to mitigate concerns around battery usage, but `MGLMapboxEvents` has since evolved to tread much lighter on the battery. There’s no longer any need for the client to call these methods directly. The iOS test project now includes MGLMapboxEvents.h explicitly to avoid having to package a header that will go unused.
A typo in a selector literal meant that `-[MGLMapViewDelegate mapViewDidFailLoadingMap:withError:]` would never be sent to delegates even if `MGLMapView` had called it. Along for the ride, create a proper `NSError` to pass into that callback, and an error domain for that error.
`MGLMapboxEvents` automatically recreates its location manager when the host app is reauthorized for Location Services. Added some redundancy to ensure that there is no location manager when either Location Services or Mapbox Metrics is off.
The shared `MGLMapboxEvents` now owns the only instance of `MGLMetricsLocationManager`. It also owns a `MGLMapboxEventsData` object, to which all user-specific data has been relegated. This object can be built up and torn down on the fly, whenever the opt-out preference is toggled. `MGLMapboxEvents` has also given up knowledge of the access token and now queries `MGLAccountManager` for that information, which `MGLMapView` keeps up-to-date.
While tracking the user’s location, a double tap not near the user dot now turns off location tracking instead of bouncing between the tapped location and the user location.
Both Android and iOS now use pause/resume. The map thread is
always running, and be able to receive messages. When paused,
it will just refuse to render.
