Added unit annotation supports onto tsmon in go.

common/tsmon/callback_test.go

 // Copyright 2016 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 tsmon
 
 import (
         "testing"
         "time"
 
@@ skipping 17 matching lines @@
         Convey("Callback is run on Flush", t, func() {
                 c, s, m := WithFakes(c)
 
                 RegisterCallbackIn(c, func(c context.Context) {
                         s.Cells = append(s.Cells, types.Cell{
                                 types.MetricInfo{
                                         Name:      "foo",
                                         Fields:    []field.Field{},
                                         ValueType: types.StringType,
                                 },
+                                types.MetricMetadata{},
                                 types.CellData{
                                         FieldVals: []interface{}{},
                                         ResetTime: time.Unix(1234, 1000),
                                         Value:     "bar",
                                 },
                         })
                 })
 
                 So(Flush(c), ShouldBeNil)
 
                 So(len(m.Cells), ShouldEqual, 1)
                 So(len(m.Cells[0]), ShouldEqual, 1)
                 So(m.Cells[0][0], ShouldResemble, types.Cell{
                         types.MetricInfo{
                                 Name:      "foo",
                                 Fields:    []field.Field{},
                                 ValueType: types.StringType,
                         },
+                        types.MetricMetadata{},
                         types.CellData{
                                 FieldVals: []interface{}{},
                                 ResetTime: time.Unix(1234, 1000),
                                 Value:     "bar",
                         },
                 })
         })
 }