Add start-up test for flutter_view sample (#8892)

* Add start-up test for flutter_view sample

* add reportMetrics flag to startup test

* rewording in manifest.yaml

dev/devicelab/bin/tasks/flutter_view__start_up.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+
+import 'package:flutter_devicelab/tasks/perf_tests.dart';
+import 'package:flutter_devicelab/framework/adb.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+
+Future<Null> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.android;
+  await task(createFlutterViewStartupTest());
+}

dev/devicelab/bin/tasks/flutter_view_ios__start_up.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+
+import 'package:flutter_devicelab/tasks/perf_tests.dart';
+import 'package:flutter_devicelab/framework/adb.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+
+Future<Null> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.ios;
+  await task(createFlutterViewStartupTest());
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -75,13 +75,21 @@ TaskFunction createGalleryBackButtonMemoryTest() {
   );
 }
 
+TaskFunction createFlutterViewStartupTest() {
+  return new StartupTest(
+      '${flutterDirectory.path}/examples/flutter_view',
+      reportMetrics: false,
+  );
+}
+
 /// Measure application startup performance.
 class StartupTest {
   static const Duration _startupTimeout = const Duration(minutes: 5);
 
-  StartupTest(this.testDirectory);
+  StartupTest(this.testDirectory, { this.reportMetrics: true });
 
   final String testDirectory;
+  final bool reportMetrics;
 
   Future<TaskResult> call() async {
     return await inDirectory(testDirectory, () async {
@@ -101,6 +109,9 @@ class StartupTest {
         deviceId,
       ]).timeout(_startupTimeout);
       final Map<String, dynamic> data = JSON.decode(file('$testDirectory/build/start_up_info.json').readAsStringSync());
+
+      if (!reportMetrics) return new TaskResult.success(data);
+
       return new TaskResult.success(data, benchmarkScoreKeys: <String>[
         'timeToFirstFrameMicros',
       ]);

dev/devicelab/manifest.yaml

@@ -144,6 +144,12 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["has-android-device"]
 
+  flutter_view__start_up:
+    description: >
+      Verifies that Flutter View can be used from an Android project.
+    stage: devicelab
+    required_agent_capabilities: ["has-android-device"]
+
   # iOS on-device tests
 
   platform_services_test_ios:
@@ -190,6 +196,12 @@ tasks:
     stage: devicelab_ios
     required_agent_capabilities: ["has-ios-device"]
 
+  flutter_view_ios__start_up:
+    description: >
+      Verifies that Flutter View can be used from an iOS project.
+    stage: devicelab_ios
+    required_agent_capabilities: ["has-ios-device"]
+
   # Tests running on Windows host
 
   flutter_gallery_win__build:

examples/flutter_view/android/app/src/main/java/com/example/view/MainActivity.java

@@ -9,7 +9,7 @@ import android.widget.TextView;
 import io.flutter.plugin.common.FlutterMessageChannel;
 import io.flutter.plugin.common.FlutterMessageChannel.MessageHandler;
 import io.flutter.plugin.common.FlutterMessageChannel.Reply;
-import io.flutter.plugin.common.StringMessageCodec;
+import io.flutter.plugin.common.StringCodec;
 import io.flutter.view.FlutterMain;
 import io.flutter.view.FlutterView;
 import java.util.ArrayList;
@@ -58,7 +58,7 @@ public class MainActivity extends AppCompatActivity {
         flutterView.runFromBundle(FlutterMain.findAppBundlePath(getApplicationContext()), null);
 
         messageChannel =
-            new FlutterMessageChannel<String>(flutterView, CHANNEL, StringMessageCodec.INSTANCE);
+            new FlutterMessageChannel<String>(flutterView, CHANNEL, StringCodec.INSTANCE);
         messageChannel.
             setMessageHandler(new MessageHandler<String>() {
                 @Override