[core] Make the BackgroundScheduler a singleton

- Do not carry it over everywhere as parameter, it is a shared
  instance anyway and the lifecycle is pretty much the app lifecycle
  from the moment we instantiate a map.
- Rename to BackgroundScheduler because it is a Scheduler that will
  do tasks in the background, we don't make assumptions if it is a
  thread pool or a single thread.
- Most importantly, remove the dependency from `core` on `platform`.

1 files changed, 0 insertions, 2 deletions

diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index 2fdd72dcb8..b1d4b14e4f 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -22,7 +22,6 @@
 
 namespace mbgl {
 
-class Scheduler;
 class RendererFrontend;
 
 namespace style {
@@ -34,7 +33,6 @@ class Map : private util::noncopyable {
 public:
     explicit Map(RendererFrontend&,
                  MapObserver&,
-                 Scheduler&,
                  const MapOptions&,
                  const ResourceOptions&);
     ~Map();