Remove dependency on glog

Addresses part of #217.

grpclog/logger.go

@@ -39,19 +39,10 @@ package grpclog // import "google.golang.org/grpc/grpclog"
 import (
 	"log"
 	"os"
-
-	"github.com/golang/glog"
 )
 
-var (
-	// GLogger is a Logger that uses glog. This is the default logger.
-	GLogger Logger = &glogger{}
-
-	// StdLogger is a Logger that uses golang's standard logger.
-	StdLogger Logger = log.New(os.Stderr, "", log.LstdFlags)
-
-	logger = GLogger
-)
+// Use golang's standard logger by default.
+var logger Logger = log.New(os.Stderr, "", log.LstdFlags)
 
 // Logger mimics golang's standard Logger as an interface.
 type Logger interface {
@@ -97,29 +88,3 @@ func Printf(format string, args ...interface{}) {
 func Println(args ...interface{}) {
 	logger.Println(args...)
 }
-
-type glogger struct{}
-
-func (g *glogger) Fatal(args ...interface{}) {
-	glog.Fatal(args...)
-}
-
-func (g *glogger) Fatalf(format string, args ...interface{}) {
-	glog.Fatalf(format, args...)
-}
-
-func (g *glogger) Fatalln(args ...interface{}) {
-	glog.Fatalln(args...)
-}
-
-func (g *glogger) Print(args ...interface{}) {
-	glog.Info(args...)
-}
-
-func (g *glogger) Printf(format string, args ...interface{}) {
-	glog.Infof(format, args...)
-}
-
-func (g *glogger) Println(args ...interface{}) {
-	glog.Infoln(args...)
-}