Cleanup useless metrics.go for garbagecollector

The metrics of garbagecollector are already published with the
workqueue metrics, so metrics.go is useless, let's cleanup it.
See https://github.com/kubernetes/client-go/blob/master/util/workqueue/metrics.go.

pkg/controller/garbagecollector/BUILD

@@ -15,7 +15,6 @@ go_library(
         "garbagecollector.go",
         "graph.go",
         "graph_builder.go",
-        "metrics.go",
         "operations.go",
         "patch.go",
         "rate_limiter_helper.go",
@@ -31,7 +30,6 @@ go_library(
         "//pkg/util/workqueue/prometheus:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/github.com/golang/groupcache/lru:go_default_library",
-        "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/api/meta:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
@@ -39,7 +37,6 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
-        "//vendor/k8s.io/apimachinery/pkg/util/clock:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/errors:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",

pkg/controller/garbagecollector/garbagecollector.go

@@ -137,8 +137,6 @@ func (gc *GarbageCollector) Run(workers int, stopCh <-chan struct{}) {
 		go wait.Until(gc.runAttemptToOrphanWorker, 1*time.Second, stopCh)
 	}
 
-	Register()
-
 	<-stopCh
 }
 

pkg/controller/garbagecollector/metrics.go

@@ -1,73 +0,0 @@
-/*
-Copyright 2016 The Kubernetes 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,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package garbagecollector
-
-import (
-	"sync"
-	"time"
-
-	"k8s.io/apimachinery/pkg/util/clock"
-
-	"github.com/prometheus/client_golang/prometheus"
-)
-
-const (
-	GarbageCollectSubsystem    = "garbage_collector"
-	EventProcessingLatencyKey  = "event_processing_latency_microseconds"
-	DirtyProcessingLatencyKey  = "dirty_processing_latency_microseconds"
-	OrphanProcessingLatencyKey = "orphan_processing_latency_microseconds"
-)
-
-var (
-	EventProcessingLatency = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Subsystem: GarbageCollectSubsystem,
-			Name:      EventProcessingLatencyKey,
-			Help:      "Time in microseconds of an event spend in the eventQueue",
-		},
-	)
-	DirtyProcessingLatency = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Subsystem: GarbageCollectSubsystem,
-			Name:      DirtyProcessingLatencyKey,
-			Help:      "Time in microseconds of an item spend in the dirtyQueue",
-		},
-	)
-	OrphanProcessingLatency = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Subsystem: GarbageCollectSubsystem,
-			Name:      OrphanProcessingLatencyKey,
-			Help:      "Time in microseconds of an item spend in the orphanQueue",
-		},
-	)
-)
-
-var registerMetrics sync.Once
-
-// Register all metrics.
-func Register() {
-	// Register the metrics.
-	registerMetrics.Do(func() {
-		prometheus.MustRegister(EventProcessingLatency)
-		prometheus.MustRegister(DirtyProcessingLatency)
-		prometheus.MustRegister(OrphanProcessingLatency)
-	})
-}
-
-func sinceInMicroseconds(clock clock.Clock, start time.Time) float64 {
-	return float64(clock.Since(start).Nanoseconds() / time.Microsecond.Nanoseconds())
-}