[flutter_tools] add timeline ANR integration test (#79991)

packages/flutter_tools/test/integration.shard/test_data/basic_project.dart

@@ -55,6 +55,50 @@ class BasicProject extends Project {
   int get topLevelFunctionBreakpointLine => lineContaining(main, '// TOP LEVEL BREAKPOINT');
 }
 
+class BasicProjectWithTimelineTraces extends Project {
+  @override
+  final String pubspec = '''
+  name: test
+  environment:
+    sdk: ">=2.12.0-0 <3.0.0"
+
+  dependencies:
+    flutter:
+      sdk: flutter
+  ''';
+
+  @override
+  final String main = r'''
+  import 'dart:async';
+  import 'dart:developer';
+
+  import 'package:flutter/material.dart';
+
+  Future<void> main() async {
+    while (true) {
+      runApp(new MyApp());
+      await Future.delayed(const Duration(milliseconds: 50));
+      Timeline.instantSync('main');
+    }
+  }
+
+  class MyApp extends StatelessWidget {
+    @override
+    Widget build(BuildContext context) {
+      topLevelFunction();
+      return new MaterialApp( // BUILD BREAKPOINT
+        title: 'Flutter Demo',
+        home: new Container(),
+      );
+    }
+  }
+
+  topLevelFunction() {
+    print("topLevelFunction"); // TOP LEVEL BREAKPOINT
+  }
+  ''';
+}
+
 class BasicProjectWithFlutterGen extends Project {
   @override
   final String generatedFile = '''

packages/flutter_tools/test/integration.shard/test_driver.dart

@@ -843,7 +843,11 @@ class SourcePosition {
 
 Future<Isolate> waitForExtension(VmService vmService, String extension) async {
   final Completer<void> completer = Completer<void>();
-  await vmService.streamListen(EventStreams.kExtension);
+  try {
+    await vmService.streamListen(EventStreams.kExtension);
+  } on RPCError {
+    // Do nothing, already subscribed.
+  }
   vmService.onExtensionEvent.listen((Event event) {
     if (event.json['extensionKind'] == 'Flutter.FrameworkInitialization') {
       completer.complete();

packages/flutter_tools/test/integration.shard/timeline_test.dart

@@ -0,0 +1,83 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// @dart = 2.8
+
+import 'dart:async';
+
+import 'package:file/file.dart';
+import 'package:vm_service/vm_service.dart';
+import 'package:vm_service/vm_service_io.dart';
+
+import '../src/common.dart';
+import 'test_data/basic_project.dart';
+import 'test_driver.dart';
+import 'test_utils.dart';
+
+void main() {
+  Directory tempDir;
+  FlutterRunTestDriver flutter;
+  VmService vmService;
+
+  setUp(() async {
+    tempDir = createResolvedTempDirectorySync('vmservice_integration_test.');
+
+    final BasicProjectWithTimelineTraces project = BasicProjectWithTimelineTraces();
+    await project.setUpIn(tempDir);
+
+    flutter = FlutterRunTestDriver(tempDir);
+    await flutter.run(withDebugger: true);
+    final int port = flutter.vmServicePort;
+    vmService = await vmServiceConnectUri('ws://localhost:$port/ws');
+  });
+
+  tearDown(() async {
+    await flutter?.stop();
+    tryToDelete(tempDir);
+  });
+
+  // Regression test for https://github.com/flutter/flutter/issues/79498
+  testWithoutContext('Can connect to the timeline without getting ANR from the application', () async {
+    final Timer timer = Timer(const Duration(minutes: 5), () {
+      print(
+        'Warning: test isolate is still active after 5 minutes. This is likely an '
+        'app-not-responding error and not a flake. See https://github.com/flutter/flutter/issues/79498 '
+        'for the bug this test is attempting to exercise.'
+      );
+    });
+
+    // Subscribe to all available streams.
+    await Future.wait(<Future<void>>[
+      vmService.streamListen(EventStreams.kVM),
+      vmService.streamListen(EventStreams.kIsolate),
+      vmService.streamListen(EventStreams.kDebug),
+      vmService.streamListen(EventStreams.kGC),
+      vmService.streamListen(EventStreams.kExtension),
+      vmService.streamListen(EventStreams.kTimeline),
+      vmService.streamListen(EventStreams.kLogging),
+      vmService.streamListen(EventStreams.kService),
+      vmService.streamListen(EventStreams.kHeapSnapshot),
+      vmService.streamListen(EventStreams.kStdout),
+      vmService.streamListen(EventStreams.kStderr),
+    ]);
+
+
+    // Verify that the app can be interacted with by querying the brightness
+    // for 30 seconds. Once this time has elapsed, wait for any pending requests and
+    // exit. If the app stops responding, the requests made will hang.
+    bool interactionCompleted = false;
+    Timer(const Duration(seconds: 30), () {
+      interactionCompleted = true;
+    });
+    final Isolate isolate = await waitForExtension(vmService, 'ext.flutter.brightnessOverride');
+    while (!interactionCompleted) {
+      final Response response = await vmService.callServiceExtension(
+        'ext.flutter.brightnessOverride',
+        isolateId: isolate.id,
+      );
+      expect(response.json['value'], 'Brightness.light');
+    }
+    timer.cancel();
+  });
+}