some polish

clientconn.go

@@ -296,8 +296,6 @@ const (
 	TransientFailure
 	// Shutdown indicates the ClientConn has started shutting down.
 	Shutdown
-	// Drain
-	Drain
 )
 
 func (s ConnectivityState) String() string {
@@ -312,8 +310,6 @@ func (s ConnectivityState) String() string {
 		return "TRANSIENT_FAILURE"
 	case Shutdown:
 		return "SHUTDOWN"
-	case Drain:
-		return "DRAIN"
 	default:
 		panic(fmt.Sprintf("unknown connectivity state: %d", s))
 	}

test/end2end_test.go

@@ -2282,8 +2282,8 @@ func leakCheck(t testing.TB) func() {
 	}
 	return func() {
 		// Loop, waiting for goroutines to shut down.
-		// Wait up to 5 seconds, but finish as quickly as possible.
-		deadline := time.Now().Add(5 * time.Second)
+		// Wait up to 10 seconds, but finish as quickly as possible.
+		deadline := time.Now().Add(10 * time.Second)
 		for {
 			var leaked []string
 			for _, g := range interestingGoroutines() {