LibWeb: Indicate that we may be able to play video MIME types

Author: https://github.com/trflynn89
Commit: 5f9fc5aedc
Pull-request: https://github.com/SerenityOS/serenity/pull/18183
Reviewed-by: https://github.com/Lubrsi
Reviewed-by: https://github.com/linusg ✅
Reviewed-by: https://github.com/skyrising

Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h

@@ -30,7 +30,7 @@ public:
     };
     NetworkState network_state() const { return m_network_state; }
 
-    Bindings::CanPlayTypeResult can_play_type(DeprecatedString const& type) const;
+    WebIDL::ExceptionOr<Bindings::CanPlayTypeResult> can_play_type(DeprecatedString const& type) const;
 
     void load() const;
     void pause() const;