Make the rest of the services have a similar raw/user interface structure.

service/taskqueue/taskqueue.go

Index: service/taskqueue/taskqueue.go
diff --git a/service/taskqueue/taskqueue.go b/service/taskqueue/taskqueue.go
new file mode 100644
index 0000000000000000000000000000000000000000..97ab2ffe60d506ccac863e557b157855fb930533
--- /dev/null
+++ b/service/taskqueue/taskqueue.go
@@ -0,0 +1,82 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package taskqueue
+
+import (
+	"github.com/luci/luci-go/common/errors"
+	"golang.org/x/net/context"
+)
+
+type taskqueueImpl struct{ RawInterface }
+
+func (t *taskqueueImpl) NewTask(path string) *Task {
+	return &Task{Path: path}
+}
+
+func (t *taskqueueImpl) Add(task *Task, queueName string) error {
+	return errors.SingleError(t.AddMulti([]*Task{task}, queueName))
+}
+
+func (t *taskqueueImpl) Delete(task *Task, queueName string) error {
+	return errors.SingleError(t.DeleteMulti([]*Task{task}, queueName))
+}
+
+func (t *taskqueueImpl) AddMulti(tasks []*Task, queueName string) error {
+	lme := errors.LazyMultiError{Size: len(tasks)}
+	i := 0
+	err := t.RawInterface.AddMulti(tasks, queueName, func(t *Task, err error) {
+		if !lme.Assign(i, err) {
+			*tasks[i] = *t
+		}
+		i++
+	})
+	if err == nil {
+		err = lme.Get()
+	}
+	return err
+}
+
+func (t *taskqueueImpl) DeleteMulti(tasks []*Task, queueName string) error {
+	lme := errors.LazyMultiError{Size: len(tasks)}
+	i := 0
+	err := t.RawInterface.DeleteMulti(tasks, queueName, func(err error) {
+		lme.Assign(i, err)
+		i++
+	})
+	if err == nil {
+		err = lme.Get()
+	}
+	return err
+}
+
+func (t *taskqueueImpl) Purge(queueName string) error {
+	return t.RawInterface.Purge(queueName)
+}
+
+func (t *taskqueueImpl) Stats(queueNames ...string) ([]Statistics, error) {
+	ret := make([]Statistics, len(queueNames))
+	lme := errors.LazyMultiError{Size: len(queueNames)}
+	i := 0
+	err := t.RawInterface.Stats(queueNames, func(s *Statistics, err error) {
+		if !lme.Assign(i, err) {
+			ret[i] = *s
+		}
+		i++
+	})
+	if err == nil {
+		err = lme.Get()
+	}
+	return ret, err
+}
+
+func (t *taskqueueImpl) Raw() RawInterface {
+	return t.RawInterface
+}
+
+var _ Interface = (*taskqueueImpl)(nil)
+
+func Get(c context.Context) Interface {
+	return &taskqueueImpl{GetRaw(c)}
+}