diff --git a/androidmk/cmd/androidmk/android.go b/androidmk/cmd/androidmk/android.go
index 9276eb5..52bcf9c 100644
--- a/androidmk/cmd/androidmk/android.go
+++ b/androidmk/cmd/androidmk/android.go
@@ -201,6 +201,7 @@
 			"LOCAL_DEX_PREOPT_GENERATE_PROFILE": "dex_preopt.profile_guided",
 
 			"LOCAL_PRIVATE_PLATFORM_APIS": "platform_apis",
+			"LOCAL_JETIFIER_ENABLED":      "jetifier",
 		})
 }
 
diff --git a/androidmk/cmd/androidmk/androidmk_test.go b/androidmk/cmd/androidmk/androidmk_test.go
index b2c3fab..f2dc6ff 100644
--- a/androidmk/cmd/androidmk/androidmk_test.go
+++ b/androidmk/cmd/androidmk/androidmk_test.go
@@ -631,12 +631,14 @@
 			LOCAL_SRC_FILES := test.jar
 			LOCAL_MODULE_CLASS := JAVA_LIBRARIES
 			LOCAL_STATIC_ANDROID_LIBRARIES :=
+			LOCAL_JETIFIER_ENABLED := true
 			include $(BUILD_PREBUILT)
 		`,
 		expected: `
 			java_import {
 				jars: ["test.jar"],
 
+				jetifier: true,
 			}
 		`,
 	},
diff --git a/cc/stl.go b/cc/stl.go
index 5e61e1e..e59f677 100644
--- a/cc/stl.go
+++ b/cc/stl.go
@@ -66,7 +66,7 @@
 		}
 		if ctx.useSdk() && ctx.Device() {
 			switch s {
-			case "":
+			case "", "system":
 				return "ndk_system"
 			case "c++_shared", "c++_static":
 				return "ndk_lib" + s
diff --git a/cc/test.go b/cc/test.go
index c3fadbd..045cc4f 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -30,6 +30,12 @@
 	Isolated *bool
 }
 
+// Test option struct.
+type TestOptions struct {
+	// The UID that you want to run the test as on a device.
+	Run_test_as *string
+}
+
 type TestBinaryProperties struct {
 	// Create a separate binary for each source file.  Useful when there is
 	// global state that can not be torn down and reset between each test suite.
@@ -55,6 +61,9 @@
 	// the name of the test configuration template (for example "AndroidTestTemplate.xml") that
 	// should be installed with the module.
 	Test_config_template *string `android:"path,arch_variant"`
+
+	// Test options.
+	Test_options TestOptions
 }
 
 func init() {
@@ -258,6 +267,11 @@
 	if Bool(test.testDecorator.Properties.Isolated) {
 		optionsMap["not-shardable"] = "true"
 	}
+
+	if test.Properties.Test_options.Run_test_as != nil {
+		optionsMap["run-test-as"] = String(test.Properties.Test_options.Run_test_as)
+	}
+
 	test.testConfig = tradefed.AutoGenNativeTestConfig(ctx, test.Properties.Test_config,
 		test.Properties.Test_config_template,
 		test.Properties.Test_suites, optionsMap)
diff --git a/java/aar.go b/java/aar.go
index ba9e187..a993bf6 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -446,7 +446,7 @@
 	Libs        []string
 
 	// if set to true, run Jetifier against .aar file. Defaults to false.
-	Jetifier_enabled *bool
+	Jetifier *bool
 }
 
 type AARImport struct {
@@ -540,7 +540,7 @@
 	aarName := ctx.ModuleName() + ".aar"
 	var aar android.Path
 	aar = android.PathForModuleSrc(ctx, a.properties.Aars[0])
-	if Bool(a.properties.Jetifier_enabled) {
+	if Bool(a.properties.Jetifier) {
 		inputFile := aar
 		aar = android.PathForModuleOut(ctx, "jetifier", aarName)
 		TransformJetifier(ctx, aar.(android.WritablePath), inputFile)
diff --git a/java/java.go b/java/java.go
index 3eae932..1fd0a9e 100644
--- a/java/java.go
+++ b/java/java.go
@@ -1726,7 +1726,7 @@
 	Exclude_dirs []string
 
 	// if set to true, run Jetifier against .jar file. Defaults to false.
-	Jetifier_enabled *bool
+	Jetifier *bool
 }
 
 type Import struct {
@@ -1771,7 +1771,7 @@
 	outputFile := android.PathForModuleOut(ctx, "combined", jarName)
 	TransformJarsToJar(ctx, outputFile, "for prebuilts", jars, android.OptionalPath{},
 		false, j.properties.Exclude_files, j.properties.Exclude_dirs)
-	if Bool(j.properties.Jetifier_enabled) {
+	if Bool(j.properties.Jetifier) {
 		inputFile := outputFile
 		outputFile = android.PathForModuleOut(ctx, "jetifier", jarName)
 		TransformJetifier(ctx, outputFile, inputFile)
diff --git a/java/jdeps.go b/java/jdeps.go
index 2eaeab8..18498be 100644
--- a/java/jdeps.go
+++ b/java/jdeps.go
@@ -51,6 +51,10 @@
 	moduleInfos := make(map[string]android.IdeInfo)
 
 	ctx.VisitAllModules(func(module android.Module) {
+		if !module.Enabled() {
+			return
+		}
+
 		ideInfoProvider, ok := module.(android.IDEInfo)
 		if !ok {
 			return
diff --git a/java/prebuilt_apis.go b/java/prebuilt_apis.go
index 02b9b45..c370811 100644
--- a/java/prebuilt_apis.go
+++ b/java/prebuilt_apis.go
@@ -22,13 +22,6 @@
 	"github.com/google/blueprint/proptools"
 )
 
-// prebuilt_apis is a meta-module that generates filegroup modules for all
-// API txt files found under the directory where the Android.bp is located.
-// Specificaly, an API file located at ./<ver>/<scope>/api/<module>.txt
-// generates a filegroup module named <module>-api.<scope>.<ver>.
-//
-// It also creates <module>-api.<scope>.latest for the lastest <ver>.
-//
 func init() {
 	android.RegisterModuleType("prebuilt_apis", PrebuiltApisFactory)
 
@@ -188,6 +181,12 @@
 	}
 }
 
+// prebuilt_apis is a meta-module that generates filegroup modules for all
+// API txt files found under the directory where the Android.bp is located.
+// Specifically, an API file located at ./<ver>/<scope>/api/<module>.txt
+// generates a filegroup module named <module>-api.<scope>.<ver>.
+//
+// It also creates <module>-api.<scope>.latest for the latest <ver>.
 func PrebuiltApisFactory() android.Module {
 	module := &prebuiltApis{}
 	module.AddProperties(&module.properties)
diff --git a/ui/build/ninja.go b/ui/build/ninja.go
index cb41579..7994f3a 100644
--- a/ui/build/ninja.go
+++ b/ui/build/ninja.go
@@ -31,7 +31,8 @@
 	defer ctx.EndTrace()
 
 	fifo := filepath.Join(config.OutDir(), ".ninja_fifo")
-	status.NinjaReader(ctx, ctx.Status.StartTool(), fifo)
+	nr := status.NewNinjaReader(ctx, ctx.Status.StartTool(), fifo)
+	defer nr.Close()
 
 	executable := config.PrebuiltBuildTool("ninja")
 	args := []string{
diff --git a/ui/build/soong.go b/ui/build/soong.go
index c89f0d5..2ce1ac9 100644
--- a/ui/build/soong.go
+++ b/ui/build/soong.go
@@ -109,7 +109,8 @@
 		defer ctx.EndTrace()
 
 		fifo := filepath.Join(config.OutDir(), ".ninja_fifo")
-		status.NinjaReader(ctx, ctx.Status.StartTool(), fifo)
+		nr := status.NewNinjaReader(ctx, ctx.Status.StartTool(), fifo)
+		defer nr.Close()
 
 		cmd := Command(ctx, config, "soong "+name,
 			config.PrebuiltBuildTool("ninja"),
diff --git a/ui/logger/logger.go b/ui/logger/logger.go
index 58890e9..9b26ae8 100644
--- a/ui/logger/logger.go
+++ b/ui/logger/logger.go
@@ -180,12 +180,16 @@
 	return s
 }
 
+type panicWriter struct{}
+
+func (panicWriter) Write([]byte) (int, error) { panic("write to panicWriter") }
+
 // Close disables logging to the file and closes the file handle.
 func (s *stdLogger) Close() {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 	if s.file != nil {
-		s.fileLogger.SetOutput(ioutil.Discard)
+		s.fileLogger.SetOutput(panicWriter{})
 		s.file.Close()
 		s.file = nil
 	}
diff --git a/ui/status/Android.bp b/ui/status/Android.bp
index 76caaef..901a713 100644
--- a/ui/status/Android.bp
+++ b/ui/status/Android.bp
@@ -28,6 +28,7 @@
     ],
     testSrcs: [
         "kati_test.go",
+        "ninja_test.go",
         "status_test.go",
     ],
 }
diff --git a/ui/status/ninja.go b/ui/status/ninja.go
index 4ceb5ef..ee2a2da 100644
--- a/ui/status/ninja.go
+++ b/ui/status/ninja.go
@@ -20,6 +20,7 @@
 	"io"
 	"os"
 	"syscall"
+	"time"
 
 	"github.com/golang/protobuf/proto"
 
@@ -27,9 +28,9 @@
 	"android/soong/ui/status/ninja_frontend"
 )
 
-// NinjaReader reads the protobuf frontend format from ninja and translates it
+// NewNinjaReader reads the protobuf frontend format from ninja and translates it
 // into calls on the ToolStatus API.
-func NinjaReader(ctx logger.Logger, status ToolStatus, fifo string) {
+func NewNinjaReader(ctx logger.Logger, status ToolStatus, fifo string) *NinjaReader {
 	os.Remove(fifo)
 
 	err := syscall.Mkfifo(fifo, 0666)
@@ -37,14 +38,69 @@
 		ctx.Fatalf("Failed to mkfifo(%q): %v", fifo, err)
 	}
 
-	go ninjaReader(status, fifo)
+	n := &NinjaReader{
+		status: status,
+		fifo:   fifo,
+		done:   make(chan bool),
+		cancel: make(chan bool),
+	}
+
+	go n.run()
+
+	return n
 }
 
-func ninjaReader(status ToolStatus, fifo string) {
-	f, err := os.Open(fifo)
-	if err != nil {
-		status.Error(fmt.Sprintf("Failed to open fifo: %v", err))
+type NinjaReader struct {
+	status ToolStatus
+	fifo   string
+	done   chan bool
+	cancel chan bool
+}
+
+const NINJA_READER_CLOSE_TIMEOUT = 5 * time.Second
+
+// Close waits for NinjaReader to finish reading from the fifo, or 5 seconds.
+func (n *NinjaReader) Close() {
+	// Signal the goroutine to stop if it is blocking opening the fifo.
+	close(n.cancel)
+
+	timeoutCh := time.After(NINJA_READER_CLOSE_TIMEOUT)
+
+	select {
+	case <-n.done:
+		// Nothing
+	case <-timeoutCh:
+		n.status.Error(fmt.Sprintf("ninja fifo didn't finish after %s", NINJA_READER_CLOSE_TIMEOUT.String()))
 	}
+
+	return
+}
+
+func (n *NinjaReader) run() {
+	defer close(n.done)
+
+	// Opening the fifo can block forever if ninja never opens the write end, do it in a goroutine so this
+	// method can exit on cancel.
+	fileCh := make(chan *os.File)
+	go func() {
+		f, err := os.Open(n.fifo)
+		if err != nil {
+			n.status.Error(fmt.Sprintf("Failed to open fifo: %v", err))
+			close(fileCh)
+			return
+		}
+		fileCh <- f
+	}()
+
+	var f *os.File
+
+	select {
+	case f = <-fileCh:
+		// Nothing
+	case <-n.cancel:
+		return
+	}
+
 	defer f.Close()
 
 	r := bufio.NewReader(f)
@@ -55,7 +111,7 @@
 		size, err := readVarInt(r)
 		if err != nil {
 			if err != io.EOF {
-				status.Error(fmt.Sprintf("Got error reading from ninja: %s", err))
+				n.status.Error(fmt.Sprintf("Got error reading from ninja: %s", err))
 			}
 			return
 		}
@@ -64,9 +120,9 @@
 		_, err = io.ReadFull(r, buf)
 		if err != nil {
 			if err == io.EOF {
-				status.Print(fmt.Sprintf("Missing message of size %d from ninja\n", size))
+				n.status.Print(fmt.Sprintf("Missing message of size %d from ninja\n", size))
 			} else {
-				status.Error(fmt.Sprintf("Got error reading from ninja: %s", err))
+				n.status.Error(fmt.Sprintf("Got error reading from ninja: %s", err))
 			}
 			return
 		}
@@ -74,13 +130,13 @@
 		msg := &ninja_frontend.Status{}
 		err = proto.Unmarshal(buf, msg)
 		if err != nil {
-			status.Print(fmt.Sprintf("Error reading message from ninja: %v", err))
+			n.status.Print(fmt.Sprintf("Error reading message from ninja: %v", err))
 			continue
 		}
 
 		// Ignore msg.BuildStarted
 		if msg.TotalEdges != nil {
-			status.SetTotalActions(int(msg.TotalEdges.GetTotalEdges()))
+			n.status.SetTotalActions(int(msg.TotalEdges.GetTotalEdges()))
 		}
 		if msg.EdgeStarted != nil {
 			action := &Action{
@@ -88,7 +144,7 @@
 				Outputs:     msg.EdgeStarted.Outputs,
 				Command:     msg.EdgeStarted.GetCommand(),
 			}
-			status.StartAction(action)
+			n.status.StartAction(action)
 			running[msg.EdgeStarted.GetId()] = action
 		}
 		if msg.EdgeFinished != nil {
@@ -101,7 +157,7 @@
 					err = fmt.Errorf("exited with code: %d", exitCode)
 				}
 
-				status.FinishAction(ActionResult{
+				n.status.FinishAction(ActionResult{
 					Action: started,
 					Output: msg.EdgeFinished.GetOutput(),
 					Error:  err,
@@ -112,17 +168,17 @@
 			message := "ninja: " + msg.Message.GetMessage()
 			switch msg.Message.GetLevel() {
 			case ninja_frontend.Status_Message_INFO:
-				status.Status(message)
+				n.status.Status(message)
 			case ninja_frontend.Status_Message_WARNING:
-				status.Print("warning: " + message)
+				n.status.Print("warning: " + message)
 			case ninja_frontend.Status_Message_ERROR:
-				status.Error(message)
+				n.status.Error(message)
 			default:
-				status.Print(message)
+				n.status.Print(message)
 			}
 		}
 		if msg.BuildFinished != nil {
-			status.Finish()
+			n.status.Finish()
 		}
 	}
 }
diff --git a/ui/status/ninja_test.go b/ui/status/ninja_test.go
new file mode 100644
index 0000000..c400c97
--- /dev/null
+++ b/ui/status/ninja_test.go
@@ -0,0 +1,45 @@
+// Copyright 2019 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package status
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"android/soong/ui/logger"
+)
+
+// Tests that closing the ninja reader when nothing has opened the other end of the fifo is fast.
+func TestNinjaReader_Close(t *testing.T) {
+	tempDir, err := ioutil.TempDir("", "ninja_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	stat := &Status{}
+	nr := NewNinjaReader(logger.New(ioutil.Discard), stat.StartTool(), filepath.Join(tempDir, "fifo"))
+
+	start := time.Now()
+
+	nr.Close()
+
+	if g, w := time.Since(start), NINJA_READER_CLOSE_TIMEOUT; g >= w {
+		t.Errorf("nr.Close timed out, %s > %s", g, w)
+	}
+}