refs #1125, 1813: update user dot tracking in one place

Now that we have cleanup around the map viewport change notifications,
this only needs to happen in one place: the GL frame draw loop.

platform/ios/MGLMapView.mm

@@ -688,6 +688,8 @@ - (void)glkView:(__unused GLKView *)view drawInRect:(__unused CGRect)rect
  _mbglMap->setSourceTileCacheSize(cacheSize);
 
  _mbglMap->renderSync();
+
+ [self updateUserLocationAnnotationView];
  }
 }
 
@@ -2351,8 +2353,6 @@ - (void)locationManager:(__unused CLLocationManager *)manager didUpdateToLocatio
 
  self.userLocationAnnotationView.haloLayer.hidden = ! CLLocationCoordinate2DIsValid(self.userLocation.coordinate) ||
  newLocation.horizontalAccuracy > 10;
-
- [self updateUserLocationAnnotationView];
 }
 
 - (BOOL)locationManagerShouldDisplayHeadingCalibration:(CLLocationManager *)manager
@@ -2509,8 +2509,6 @@ - (void)notifyMapChange:(mbgl::MapChange)change
  case mbgl::MapChangeRegionWillChange:
  case mbgl::MapChangeRegionWillChangeAnimated:
  {
- [self updateUserLocationAnnotationView];
-
  [self deselectAnnotation:self.selectedAnnotation animated:NO];
 
  BOOL animated = (change == mbgl::MapChangeRegionWillChangeAnimated);
@@ -2545,7 +2543,6 @@ - (void)notifyMapChange:(mbgl::MapChange)change
  }
  case mbgl::MapChangeRegionIsChanging:
  {
- [self updateUserLocationAnnotationView];
  [self updateCompass];
 
  if ([self.delegate respondsToSelector:@selector(mapViewRegionIsChanging:)])
@@ -2557,7 +2554,6 @@ - (void)notifyMapChange:(mbgl::MapChange)change
  case mbgl::MapChangeRegionDidChange:
  case mbgl::MapChangeRegionDidChangeAnimated:
  {
- [self updateUserLocationAnnotationView];
  [self updateCompass];
 
  if (self.pan.state == UIGestureRecognizerStateChanged ||