Companion PR to #6039 (#1100)

* remove on_block_imported

* remove on_block_imported

Co-authored-by: Gav Wood <gavin@parity.io>

polkadot/network/test/src/lib.rs

@@ -258,10 +258,10 @@ impl<D> Peer<D> {
 				Default::default()
 			};
 			self.block_import.import_block(import_block, cache).expect("block_import failed");
-			self.network.on_block_imported(header, true);
 			at = hash;
 		}
 
+		self.network.update_chain();
 		self.network.service().announce_block(at.clone(), Vec::new());
 		at
 	}
@@ -770,10 +770,7 @@ pub trait TestNetFactory: Sized {
 
 				// We poll `imported_blocks_stream`.
 				while let Poll::Ready(Some(notification)) = peer.imported_blocks_stream.as_mut().poll_next(cx) {
-					peer.network.on_block_imported(
-						notification.header,
-						true,
-					);
+					peer.network.service().announce_block(notification.hash, Vec::new());
 				}
 
 				// We poll `finality_notification_stream`, but we only take the last event.