Fix crash in round video playback.

Telegram/SourceFiles/media/player/media_player_round_controller.cpp

@@ -70,7 +70,9 @@ RoundController::RoundController(
 	Auth().data().itemRepaintRequest(
 	) | rpl::start_with_next([=](not_null<const HistoryItem*> item) {
 		if (item == _context) {
-			checkReaderState();
+			crl::on_main(this, [=] {
+				checkReaderState();
+			});
 		}
 	}, lifetime());
 }

Telegram/SourceFiles/media/player/media_player_round_controller.h

@@ -26,7 +26,9 @@ namespace Player {
 struct TrackState;
 enum class State;
 
-class RoundController : private base::Subscriber {
+class RoundController
+	: public base::has_weak_ptr
+	, private base::Subscriber {
 	struct CreateTag;
 
 public: