[core] map snapshotter - add attributions to snapshotter callback

platform/default/mbgl/map/map_snapshotter.cpp

@@ -76,10 +76,21 @@ void MapSnapshotter::Impl::snapshot(ActorRef<MapSnapshotter::Callback> callback)
             return transform.latLngToScreenCoordinate(unwrappedLatLng);
         }};
 
+        // Collect all source attributions
+        std::vector<std::string> attributions;
+        for (auto source : map.getStyle().getSources()) {
+            auto attribution = source->getAttribution();
+            if (attribution) {
+                attributions.push_back(*attribution);
+            }
+        }
+
+        // Invoke callback
         callback.invoke(
                 &MapSnapshotter::Callback::operator(),
                 error,
                 error ? PremultipliedImage() : frontend.readStillImage(),
+                std::move(attributions),
                 std::move(pointForFn)
         );
     });

platform/default/mbgl/map/map_snapshotter.hpp

@@ -8,6 +8,7 @@
 #include <exception>
 #include <memory>
 #include <string>
+#include <vector>
 #include <functional>
 
 namespace mbgl {
@@ -48,7 +49,8 @@ public:
     LatLngBounds getRegion() const;
 
     using PointForFn = std::function<ScreenCoordinate (const LatLng&)>;
-    using Callback = std::function<void (std::exception_ptr, PremultipliedImage, PointForFn)>;
+    using Attributions = std::vector<std::string>;
+    using Callback = std::function<void (std::exception_ptr, PremultipliedImage, Attributions, PointForFn)>;
     void snapshot(ActorRef<Callback>);
 
 private: