go: Replace Logrus with go-logging.

go/src/infra/libs/logging/go-logging.go

Index: go/src/infra/libs/logging/go-logging.go
diff --git a/go/src/infra/libs/logging/go-logging.go b/go/src/infra/libs/logging/go-logging.go
new file mode 100644
index 0000000000000000000000000000000000000000..d99d50e400e3c3a90de7fe98587d539a6a480cb8
--- /dev/null
+++ b/go/src/infra/libs/logging/go-logging.go
@@ -0,0 +1,33 @@
+// 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.
+
+// +build !appengine
+
+package logging
+
+import (
+	"os"
+
+	"github.com/op/go-logging"
+)
+
+const fmt string = "%{color}[P%{pid} %{time:15:04:05.000} %{shortfile} %{level:.4s} %{id:03x}]%{color:reset} %{message}"
+
+type logger struct {
+	l *logging.Logger
+}
+
+func (l *logger) Infof(format string, args ...interface{})    { l.l.Info(format, args...) }
+func (l *logger) Warningf(format string, args ...interface{}) { l.l.Warning(format, args...) }
+func (l *logger) Errorf(format string, args ...interface{})   { l.l.Error(format, args...) }
+
+func init() {
+	backend := logging.NewLogBackend(os.Stdout, "", 0)
+	formatted := logging.NewBackendFormatter(backend, logging.MustStringFormatter(fmt))
+	logging.SetBackend(formatted)
+
+	log := &logger{logging.MustGetLogger("")}
+	log.l.ExtraCalldepth = 1 // one layer of wrapping in logger struct above
+	DefaultLogger = log
+}