Devicelab memory usage test that navigates repeatedly to a screen within Gallery (#7137)

dev/devicelab/bin/tasks/flutter_gallery__memory_nav.dart

+// Copyright 2016 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/framework.dart';
+
+Future<Null> main() async {
+  await task(createGalleryNavigationMemoryTest());
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -52,6 +52,14 @@ TaskFunction createHelloWorldMemoryTest() {
   );
 }
 
+TaskFunction createGalleryNavigationMemoryTest() {
+  return new MemoryTest(
+    '${flutterDirectory.path}/examples/flutter_gallery',
+    'io.flutter.examples.gallery',
+    testTarget: 'test_driver/memory_nav.dart',
+  );
+}
+
 /// Measure application startup performance.
 class StartupTest {
   static const Duration _startupTimeout = const Duration(minutes: 2);

dev/devicelab/manifest.yaml

@@ -121,6 +121,12 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["has-android-device"]
 
+  flutter_gallery__memory_nav:
+    description: >
+      Measures memory usage after repeated navigation in Gallery.
+    stage: devicelab
+    required_agent_capabilities: ["has-android-device"]
+
 
   # iOS on-device tests
 

examples/flutter_gallery/test_driver/memory_nav.dart

+// Copyright 2016 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 'package:flutter_driver/driver_extension.dart';
+import 'package:flutter_gallery/main.dart' as app;
+
+void main() {
+  enableFlutterDriverExtension();
+  app.main();
+}

examples/flutter_gallery/test_driver/memory_nav_test.dart

+import 'dart:async';
+
+import 'package:flutter_driver/flutter_driver.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('flutter gallery transitions', () {
+    FlutterDriver driver;
+    setUpAll(() async {
+      driver = await FlutterDriver.connect();
+    });
+
+    tearDownAll(() async {
+      if (driver != null)
+        await driver.close();
+    });
+
+    test('navigation', () async {
+      SerializableFinder menuItem = find.text('Text fields');
+      await driver.scrollIntoView(menuItem);
+      await new Future<Null>.delayed(new Duration(milliseconds: 500));
+
+      for (int i = 0; i < 15; i++) {
+        await driver.tap(menuItem);
+        await new Future<Null>.delayed(new Duration(milliseconds: 1000));
+        await driver.tap(find.byTooltip('Back'));
+        await new Future<Null>.delayed(new Duration(milliseconds: 1000));
+      }
+    }, timeout: new Timeout(new Duration(minutes: 1)));
+  });
+}