contractcourt/chain_arbitrator: markChanClosed->notifyChanClosed

We no longer have to mark the channel as fully closed in the database,
as it is done directly in the chainWatcher. Instead, we stop the watcher
and delete it from the set of active watchers.

contractcourt/chain_arbitrator.go

@@ -341,9 +341,22 @@ func (c *ChainArbitrator) Start() error {
 				pCache:    c.cfg.PreimageDB,
 				signer:    c.cfg.Signer,
 				isOurAddr: c.cfg.IsOurAddress,
-				markChanClosed: func() error {
-					// TODO(roasbeef): also need to pass in log?
-					return c.resolveContract(chanPoint, nil)
+				notifyChanClosed: func() error {
+					c.Lock()
+					delete(c.activeChannels, chanPoint)
+
+					chainWatcher, ok := c.activeWatchers[chanPoint]
+					if ok {
+						// Since the chainWatcher is
+						// calling notifyChanClosed, we
+						// must stop it in a goroutine
+						// to not deadlock.
+						go chainWatcher.Stop()
+					}
+					delete(c.activeWatchers, chanPoint)
+					c.Unlock()
+
+					return nil
 				},
 				contractBreach: func(retInfo *lnwallet.BreachRetribution) error {
 					return c.cfg.ContractBreach(chanPoint, retInfo)
@@ -677,8 +690,21 @@ func (c *ChainArbitrator) WatchNewChannel(newChan *channeldb.OpenChannel) error
 			pCache:    c.cfg.PreimageDB,
 			signer:    c.cfg.Signer,
 			isOurAddr: c.cfg.IsOurAddress,
-			markChanClosed: func() error {
-				return c.resolveContract(chanPoint, nil)
+			notifyChanClosed: func() error {
+				c.Lock()
+				delete(c.activeChannels, chanPoint)
+
+				chainWatcher, ok := c.activeWatchers[chanPoint]
+				if ok {
+					// Since the chainWatcher is calling
+					// notifyChanClosed, we must stop it in
+					// a goroutine to not deadlock.
+					go chainWatcher.Stop()
+				}
+				delete(c.activeWatchers, chanPoint)
+				c.Unlock()
+
+				return nil
 			},
 			contractBreach: func(retInfo *lnwallet.BreachRetribution) error {
 				return c.cfg.ContractBreach(chanPoint, retInfo)