Add a major incremental build scenario to cuj metrics.

The mentioned scenario in b/152046247 would help to detect if there
is an incremental build issue.

Bug: b/145688720
Test: * m cuj_tests
      * Ran the cuj_tests and verified that the Intent.java file was
         touched. Unmarshalled the cuj_metrics.pb file and check if
	 the added scenario existed.
Change-Id: Ic6c335f005568dd77c99e4e1762383ec76d57ecb

cuj/cuj.go

@@ -35,6 +35,7 @@ import (
 type Test struct {
 	name   string
 	args   []string
+	before func() error
 
 	results TestResults
 }
@@ -119,6 +120,15 @@ func (t *Test) Run(logsDir string) {
 	t.results.metrics = met
 }
 
+// Touch the Intent.java file to cause a rebuild of the frameworks to monitor the
+// incremental build speed as mentioned b/152046247. Intent.java file was chosen
+// as it is a key component of the framework and is often modified.
+func touchIntentFile() error {
+	const intentFileName = "frameworks/base/core/java/android/content/Intent.java"
+	currentTime := time.Now().Local()
+	return os.Chtimes(intentFileName, currentTime, currentTime)
+}
+
 func main() {
 	outDir := os.Getenv("OUT_DIR")
 	if outDir == "" {
@@ -170,6 +180,36 @@ func main() {
 			name: "framework_rebuild_twice",
 			args: []string{"framework"},
 		},
+		{
+			// Scenario major_inc_build (b/152046247): tracking build speed of major incremental build.
+			name: "major_inc_build_droid",
+			args: []string{"droid"},
+		},
+		{
+			name:   "major_inc_build_framework_minus_apex_after_droid_build",
+			args:   []string{"framework-minus-apex"},
+			before: touchIntentFile,
+		},
+		{
+			name:   "major_inc_build_framework_after_droid_build",
+			args:   []string{"framework"},
+			before: touchIntentFile,
+		},
+		{
+			name:   "major_inc_build_sync_after_droid_build",
+			args:   []string{"sync"},
+			before: touchIntentFile,
+		},
+		{
+			name:   "major_inc_build_droid_rebuild",
+			args:   []string{"droid"},
+			before: touchIntentFile,
+		},
+		{
+			name:   "major_inc_build_update_api_after_droid_rebuild",
+			args:   []string{"update-api"},
+			before: touchIntentFile,
+		},
 	}
 
 	cujMetrics := metrics.NewCriticalUserJourneysMetrics()
@@ -178,6 +218,12 @@ func main() {
 	for i, t := range tests {
 		logsSubDir := fmt.Sprintf("%02d_%s", i, t.name)
 		logsDir := filepath.Join(cujDir, "logs", logsSubDir)
+		if t.before != nil {
+			if err := t.before(); err != nil {
+				fmt.Printf("error running before function on test %q: %v\n", t.name, err)
+				break
+			}
+		}
 		t.Run(logsDir)
 		if t.results.err != nil {
 			fmt.Printf("error running test %q: %s\n", t.name, t.results.err)