isolate: manage lifetime of checker and uploader in main.

client/cmd/isolate/upload_tracker.go

 // Copyright 2017 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 179 matching lines @@
         ut.checker.AddItem(isolFile.item(), true, func(item *Item, ps *isolatedclient.PushState) {
                 if ps == nil {
                         return
                 }
                 log.Printf("QUEUED %q for upload", item.RelPath)
                 ut.uploader.UploadBytes(item.RelPath, isolFile.contents(), ps, func() {
                         log.Printf("UPLOADED %q", item.RelPath)
                 })
         })
 
-        // Make sure that all pending items have been checked.
-        if err := ut.checker.Close(); err != nil {
-                return IsolatedSummary{}, err
-        }
-
-        // Make sure that all the uploads have completed successfully.
-        if err := ut.uploader.Close(); err != nil {
-                return IsolatedSummary{}, err
-        }
-
         // Write the isolated file...
         if err := isolFile.writeJSONFile(ut.lOS); err != nil {
                 return IsolatedSummary{}, err
         }
 
         return IsolatedSummary{
                 Name:   isolFile.name(),
                 Digest: isolFile.item().Digest,
         }, nil
 }
@@ skipping 43 matching lines @@
 }
 
 // name returns the base name of the isolated file, extension stripped.
 func (ij *isolatedFile) name() string {
         name := filepath.Base(ij.path)
         if i := strings.LastIndex(name, "."); i != -1 {
                 name = name[:i]
         }
         return name
 }