A devicelab memory test for Android app suspend and resume (#7164)

dev/devicelab/bin/tasks/flutter_gallery__back_button_memory.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(createGalleryBackButtonMemoryTest());
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -60,6 +60,13 @@ TaskFunction createGalleryNavigationMemoryTest() {
   );
 }
 
+TaskFunction createGalleryBackButtonMemoryTest() {
+  return new AndroidBackButtonMemoryTest(
+    '${flutterDirectory.path}/examples/flutter_gallery',
+    'io.flutter.examples.gallery',
+  );
+}
+
 /// Measure application startup performance.
 class StartupTest {
   static const Duration _startupTimeout = const Duration(minutes: 2);
@@ -256,3 +263,55 @@ class MemoryTest {
     });
   }
 }
+
+/// Measure application memory usage after pausing and resuming the app
+/// with the Android back button.
+class AndroidBackButtonMemoryTest {
+  final String testDirectory;
+  final String packageName;
+
+  AndroidBackButtonMemoryTest(this.testDirectory, this.packageName);
+
+  Future<TaskResult> call() {
+    return inDirectory(testDirectory, () async {
+      if (deviceOperatingSystem != DeviceOperatingSystem.android) {
+        throw 'This test is only supported on Android';
+      }
+
+      AndroidDevice device = await devices.workingDevice;
+      await device.unlock();
+      String deviceId = device.deviceId;
+      await flutter('packages', options: <String>['get']);
+
+      await flutter('run', options: <String>[
+        '-v',
+        '--profile',
+        '--trace-startup', // wait for the first frame to render
+        '-d',
+        deviceId,
+      ]);
+
+      Map<String, dynamic> startData = await device.getMemoryStats(packageName);
+
+      Map<String, dynamic> data = <String, dynamic>{
+         'start_total_kb': startData['total_kb'],
+      };
+
+      // Perform a series of back button suspend and resume cycles.
+      for (int i = 0; i < 10; i++) {
+        device.shellExec('input', <String>['keyevent', 'KEYCODE_BACK']);
+        await new Future<Null>.delayed(new Duration(milliseconds: 1000));
+        device.shellExec('am', <String>['start', '-n', 'io.flutter.examples.gallery/org.domokit.sky.shell.SkyActivity']);
+        await new Future<Null>.delayed(new Duration(milliseconds: 1000));
+      }
+
+      Map<String, dynamic> endData = await device.getMemoryStats(packageName);
+      data['end_total_kb'] = endData['total_kb'];
+      data['diff_total_kb'] = endData['total_kb'] - startData['total_kb'];
+
+      await device.stop(packageName);
+
+      return new TaskResult.success(data, benchmarkScoreKeys: data.keys.toList());
+    });
+  }
+}

dev/devicelab/manifest.yaml

@@ -127,6 +127,12 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["has-android-device"]
 
+  flutter_gallery__back_button_memory:
+    description: >
+      Measures memory usage after Android app suspend and resume.
+    stage: devicelab
+    required_agent_capabilities: ["has-android-device"]
+
 
   # iOS on-device tests