Milo: Add machine pool info for buildbot builder view.

milo/appengine/buildbot/build.go

Index: milo/appengine/buildbot/build.go
diff --git a/milo/appengine/buildbot/build.go b/milo/appengine/buildbot/build.go
index 9218ba1b20219d5a676d6a676c70d24b02cb311a..ad24ce047016a1e9b51f795c06abb3c2b3b96329 100644
--- a/milo/appengine/buildbot/build.go
+++ b/milo/appengine/buildbot/build.go
@@ -146,17 +146,13 @@ func summary(c context.Context, b *buildbotBuild) resp.BuildComponent {
 	started, ended, duration := parseTimes(nil, b.Times)
 
 	// Link to bot and original build.
-	server := "build.chromium.org/p"
+	host := "build.chromium.org/p"
 	if b.Internal {
-		server = "uberchromegw.corp.google.com/i"
+		host = "uberchromegw.corp.google.com/i"
 	}
 	bot := &resp.Link{
 		Label: b.Slave,
-		URL:   fmt.Sprintf("https://%s/%s/buildslaves/%s", server, b.Master, b.Slave),
-	}
-	host := "build.chromium.org/p"
-	if b.Internal {
-		host = "uberchromegw.corp.google.com/i"
+		URL:   fmt.Sprintf("https://%s/%s/buildslaves/%s", host, b.Master, b.Slave),
 	}
 	source := &resp.Link{
 		Label: fmt.Sprintf("%s/%s/%d", b.Master, b.Buildername, b.Number),