LogDog Butler: Catch SIGTERM on Linux.

client/cmd/logdog_butler/main_windows.go

Index: client/cmd/logdog_butler/main_windows.go
diff --git a/client/cmd/logdog_butler/streamserver_windows.go b/client/cmd/logdog_butler/main_windows.go
similarity index 88%
rename from client/cmd/logdog_butler/streamserver_windows.go
rename to client/cmd/logdog_butler/main_windows.go
index 7977eedd09c72aab8ff70719c6a490d06edc296c..690d501104a9d959b4705d8527fe16c791d5d32b 100644
--- a/client/cmd/logdog_butler/streamserver_windows.go
+++ b/client/cmd/logdog_butler/main_windows.go
@@ -7,6 +7,7 @@ package main
 import (
 	"errors"
 	"fmt"
+	"os"
 
 	"github.com/luci/luci-go/client/internal/logdog/butler/streamserver"
 	"golang.org/x/net/context"
@@ -19,6 +20,12 @@ const (
 	exampleStreamServerURI = streamServerURI("net.pipe:logdog-butler")
 )
 
+// interruptSignals is the set of signals to handle gracefully (e.g., flush,
+// shutdown).
+var interruptSignals = []os.Signal{
+	os.Interrupt,
+}
+
 type streamServerURI string
 
 func (u streamServerURI) Parse() (string, error) {