core: Add error reporting for corrupted symbols (#4458)

platform/default/src/mbgl/map/map_snapshotter.cpp

@@ -49,6 +49,10 @@ public:
         delegate.invoke(&RendererObserver::onStyleImageMissing, image, cb);
     }
 
+    void onSymbolError(const std::string& message) override {
+        delegate.invoke(&RendererObserver::onSymbolError, message);
+    }
+
 private:
     std::shared_ptr<Mailbox> mailbox;
     ActorRef<RendererObserver> delegate;
@@ -108,6 +112,8 @@ public:
         rendererObserver->onStyleImageMissing(id, done);
     }
 
+    void onSymbolError(const std::string& message) override { rendererObserver->onSymbolError(message); }
+
     void setObserver(std::shared_ptr<RendererObserver> observer) {
         assert(observer);
         rendererObserver = std::move(observer);