[milo] remove linkBase and calculate links directly.

milo/buildsource/buildbucket/pubsub.go

 // Copyright 2017 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package buildbucket
 
 import (
         "encoding/json"
         "errors"
         "fmt"
@@ skipping 81 matching lines @@
                 return nil, errors.New("no swarming hostname tag")
         }
         if task, ok = tags["swarming_task_id"]; !ok {
                 return nil, errors.New("no swarming task id")
         }
         swarmingSvc, err := swarming.NewProdService(c, host)
         if err != nil {
                 return nil, err
         }
         bl := swarming.BuildLoader{}
-        // The linkBase is not necessary for the summary.
-        return bl.SwarmingBuildImpl(c, swarmingSvc, "", task)
+        return bl.SwarmingBuildImpl(c, swarmingSvc, task)
 }
 
 // processBuild queries swarming and logdog for annotation data, then adds or
 // updates a buildEntry in datastore.
 func processBuild(
         c context.Context, host string, build *bucketApi.ApiCommonBuildMessage) (
         *buildEntry, error) {
 
         now := clock.Now(c).UTC()
         entry := buildEntry{key: buildEntryKey(host, build.Id)}
@@ skipping 114 matching lines @@
                 logging.WithError(err).Errorf(c, "could not parse pubsub message string")
                 return err
         }
         if err := json.Unmarshal(bData, &data); err != nil {
                 logging.WithError(err).Errorf(c, "could not parse pubsub message data")
                 return err
         }
 
         return handlePubSubBuild(c, &data)
 }