Add CUJ tests

Add a cuj_tests binary that runs through a sequence of critical
user journey builds and collects metrics.

Bug: 145688720
Test: cuj_tests
Change-Id: I6bb1a3fc4a458fd8cea7b7c924f565d0cf3e6df3

ui/metrics/metrics.go

@@ -19,9 +19,9 @@ import (
 	"os"
 	"strconv"
 
-	"android/soong/ui/metrics/metrics_proto"
-
 	"github.com/golang/protobuf/proto"
+
+	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
 )
 
 const (
@@ -137,13 +137,32 @@ func (m *Metrics) SetBuildDateTime(date_time string) {
 	}
 }
 
-func (m *Metrics) Serialize() (data []byte, err error) {
-	return proto.Marshal(&m.metrics)
-}
-
 // exports the output to the file at outputPath
 func (m *Metrics) Dump(outputPath string) (err error) {
-	data, err := m.Serialize()
+	return writeMessageToFile(&m.metrics, outputPath)
+}
+
+type CriticalUserJourneysMetrics struct {
+	cujs soong_metrics_proto.CriticalUserJourneysMetrics
+}
+
+func NewCriticalUserJourneysMetrics() *CriticalUserJourneysMetrics {
+	return &CriticalUserJourneysMetrics{}
+}
+
+func (c *CriticalUserJourneysMetrics) Add(name string, metrics *Metrics) {
+	c.cujs.Cujs = append(c.cujs.Cujs, &soong_metrics_proto.CriticalUserJourneyMetrics{
+		Name:    proto.String(name),
+		Metrics: &metrics.metrics,
+	})
+}
+
+func (c *CriticalUserJourneysMetrics) Dump(outputPath string) (err error) {
+	return writeMessageToFile(&c.cujs, outputPath)
+}
+
+func writeMessageToFile(pb proto.Message, outputPath string) (err error) {
+	data, err := proto.Marshal(pb)
 	if err != nil {
 		return err
 	}