[syslog] Add Debug,Trace constants

Change-Id: I93e09bd230213a082a8e5acd542a9b0e6af534a2
diff --git a/garnet/public/lib/syslog/go/src/syslog/logger/logger.go b/garnet/public/lib/syslog/go/src/syslog/logger/logger.go
index 9cbc6cb..33f34f2 100644
--- a/garnet/public/lib/syslog/go/src/syslog/logger/logger.go
+++ b/garnet/public/lib/syslog/go/src/syslog/logger/logger.go
@@ -44,9 +44,20 @@
 	SOCKET_DATAGRAM   = 1 << 0
 )
 
+const (
+	_ int = iota
+	DebugVerbosity
+	TraceVerbosity
+)
+
 type LogLevel int32
 
 const (
+	TraceLevel = LogLevel(-TraceVerbosity)
+	DebugLevel = LogLevel(-DebugVerbosity)
+)
+
+const (
 	InfoLevel LogLevel = iota
 	WarningLevel
 	ErrorLevel
diff --git a/garnet/public/lib/syslog/go/src/syslog/logger/logger_test.go b/garnet/public/lib/syslog/go/src/syslog/logger/logger_test.go
index e081b12..2c1b7ce 100644
--- a/garnet/public/lib/syslog/go/src/syslog/logger/logger_test.go
+++ b/garnet/public/lib/syslog/go/src/syslog/logger/logger_test.go
@@ -165,13 +165,13 @@
 func TestLoggerVerbosity(t *testing.T) {
 	sin, log := setup(t)
 	format := "integer: %d"
-	log.VLogf(2, format, 10)
+	log.VLogf(logger.TraceVerbosity, format, 10)
 	_, err := sin.Read(make([]byte, 0), 0)
 	if zerr, ok := err.(zx.Error); !ok || zerr.Status != zx.ErrShouldWait {
 		t.Fatal(err)
 	}
 	log.SetVerbosity(2)
-	log.VLogf(2, format, 10)
+	log.VLogf(logger.TraceVerbosity, format, 10)
 	expectedMsg := fmt.Sprintf(format, 10)
 	checkoutput(t, sin, expectedMsg, logger.LogLevel(-2))
 }