Update Coordinator client, add datagram assembly.

logdog/client/coordinator/list.go

Index: logdog/client/coordinator/list.go
diff --git a/logdog/client/coordinator/list.go b/logdog/client/coordinator/list.go
index 46c2538af229946d6e28bca9c5924af8896a2543..9e2fcce767b4f59c74cbcdc18a95612db23dab12 100644
--- a/logdog/client/coordinator/list.go
+++ b/logdog/client/coordinator/list.go
@@ -5,6 +5,8 @@
 package coordinator
 
 import (
+	"fmt"
+
 	"github.com/luci/luci-go/common/config"
 	"github.com/luci/luci-go/logdog/api/endpoints/coordinator/logs/v1"
 	"github.com/luci/luci-go/logdog/common/types"
@@ -86,7 +88,10 @@ func (c *Client) List(ctx context.Context, project config.ProjectName, pathBase
 			case logdog.ListResponse_Component_STREAM:
 				lr.Stream = true
 				if s.State != nil {
-					lr.State = loadLogStream(resp.Project, lr.FullPath(), s.State, s.Desc)
+					lr.State, err = loadLogStream(resp.Project, lr.FullPath(), s.State, s.Desc)
+					if err != nil {
+						return fmt.Errorf("failed to load stream state: %v", err)
+					}
 				}
 
 			case logdog.ListResponse_Component_PROJECT: