remove the flutter view cache; fix the ability to quit the app after a full restart (#11420)

* remove the flutter view cache; fix the ability to quit the app after a full restart

* improve test

* update test

dev/devicelab/bin/tasks/commands_test.dart

@@ -7,11 +7,14 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
+import 'package:vm_service_client/vm_service_client.dart';
 
 import 'package:flutter_devicelab/framework/adb.dart';
 import 'package:flutter_devicelab/framework/framework.dart';
 import 'package:flutter_devicelab/framework/utils.dart';
 
+const int kObservatoryPort = 8888;
+
 void main() {
   task(() async {
     final Device device = await devices.workingDevice;
@@ -23,13 +26,15 @@ void main() {
       print('run: starting...');
       final Process run = await startProcess(
         path.join(flutterDirectory.path, 'bin', 'flutter'),
-        <String>['run', '--verbose', '--observatory-port=8888', '-d', device.deviceId, 'lib/commands.dart'],
+        <String>['run', '--verbose', '--observatory-port=$kObservatoryPort', '-d', device.deviceId, 'lib/commands.dart'],
       );
+      final StreamController<String> stdout = new StreamController<String>.broadcast();
       run.stdout
         .transform(UTF8.decoder)
         .transform(const LineSplitter())
         .listen((String line) {
           print('run:stdout: $line');
+          stdout.add(line);
           if (line.contains(new RegExp(r'^\[\s+\] For a more detailed help message, press "h"\. To quit, press "q"\.'))) {
             print('run: ready!');
             ready.complete();
@@ -46,6 +51,9 @@ void main() {
       await Future.any<dynamic>(<Future<dynamic>>[ ready.future, run.exitCode ]);
       if (!ok)
         throw 'Failed to run test app.';
+
+      final VMServiceClient client = new VMServiceClient.connect('ws://localhost:$kObservatoryPort/ws');
+
       await drive('none');
       print('test: pressing "p" to enable debugPaintSize...');
       run.stdin.write('p');
@@ -59,10 +67,24 @@ void main() {
       print('test: pressing "P" again...');
       run.stdin.write('P');
       await drive('none');
+      final Future<String> reloadStartingText =
+        stdout.stream.firstWhere((String line) => line.endsWith('hot reload...'));
+      print('test: pressing "r" to perform a hot reload...');
+      run.stdin.write('r');
+      await reloadStartingText;
+      await drive('none');
+      final Future<String> restartStartingText =
+        stdout.stream.firstWhere((String line) => line.endsWith('full restart...'));
+      print('test: pressing "R" to perform a full reload...');
+      run.stdin.write('R');
+      await restartStartingText;
+      await drive('none');
       run.stdin.write('q');
       final int result = await run.exitCode;
       if (result != 0)
         throw 'Received unexpected exit code $result from run process.';
+      print('test: validating that the app has in fact closed...');
+      await client.done.timeout(new Duration(seconds: 5));
     });
     return new TaskResult.success(null);
   });
@@ -72,7 +94,7 @@ Future<Null> drive(String name) async {
   print('drive: running commands_$name check...');
   final Process drive = await startProcess(
     path.join(flutterDirectory.path, 'bin', 'flutter'),
-    <String>['drive', '--use-existing-app', 'http://127.0.0.1:8888/', '--keep-app-running', '--driver', 'test_driver/commands_${name}_test.dart'],
+    <String>['drive', '--use-existing-app', 'http://127.0.0.1:$kObservatoryPort/', '--keep-app-running', '--driver', 'test_driver/commands_${name}_test.dart'],
   );
   drive.stdout
     .transform(UTF8.decoder)

packages/flutter_tools/lib/src/resident_runner.dart

@@ -33,16 +33,11 @@ class FlutterDevice {
   DevFS devFS;
   ApplicationPackage package;
 
-  String _viewFilter;
   StreamSubscription<String> _loggingSubscription;
 
   FlutterDevice(this.device);
 
-  String get viewFilter => _viewFilter;
-  set viewFilter(String filter) {
-    _viewFilter = filter;
-    _viewsCache = null;
-  }
+  String viewFilter;
 
   /// If the [reloadSources] parameter is not null the 'reloadSources' service
   /// will be registered.
@@ -63,33 +58,22 @@ class FlutterDevice {
   }
 
   Future<Null> refreshViews() async {
-    if ((vmServices == null) || vmServices.isEmpty)
+    if (vmServices == null || vmServices.isEmpty)
       return;
     for (VMService service in vmServices)
       await service.vm.refreshViews();
-    _viewsCache = null;
   }
 
-  List<FlutterView> _viewsCache;
   List<FlutterView> get views {
-    if (_viewsCache == null) {
-      if ((vmServices == null) || vmServices.isEmpty)
-        return null;
-      final List<FlutterView> result = <FlutterView>[];
-      if (_viewFilter == null) {
-        for (VMService service in vmServices) {
-          if (!service.isClosed)
-            result.addAll(service.vm.views.toList());
-        }
-      } else {
-        for (VMService service in vmServices) {
-          if (!service.isClosed)
-            result.addAll(service.vm.allViewsWithName(_viewFilter));
-        }
-      }
-      _viewsCache = result;
-    }
-    return _viewsCache;
+    if (vmServices == null)
+      return <FlutterView>[];
+
+    return vmServices
+      .where((VMService service) => !service.isClosed)
+      .expand((VMService service) => viewFilter != null
+          ? service.vm.allViewsWithName(viewFilter)
+          : service.vm.views)
+      .toList();
   }
 
   Future<Null> getVMs() async {

packages/flutter_tools/lib/src/vmservice.dart

@@ -207,6 +207,10 @@ class VMService {
     final String streamId = data['streamId'];
     final Map<String, dynamic> eventData = data['event'];
     final Map<String, dynamic> eventIsolate = eventData['isolate'];
+
+    // Log event information.
+    printTrace(data.toString());
+
     ServiceEvent event;
     if (eventIsolate != null) {
       // getFromMap creates the Isolate if necessary.
@@ -336,8 +340,7 @@ abstract class ServiceObject {
     // If we don't have a model object for this service object type, as a
     // fallback return a ServiceMap object.
     serviceObject ??= new ServiceMap._empty(owner);
-    // We have now constructed an emtpy service object, call update to
-    // populate it.
+    // We have now constructed an empty service object, call update to populate it.
     serviceObject.update(map);
     return serviceObject;
   }
@@ -717,6 +720,8 @@ class VM extends ServiceObjectOwner {
     Duration timeout,
     bool timeoutFatal: true,
   }) async {
+    printTrace('$method: $params');
+
     assert(params != null);
     timeout ??= _vmService._requestTimeout;
     try {
@@ -1029,7 +1034,6 @@ class Isolate extends ServiceObjectOwner {
     return invokeRpcRaw('resume');
   }
 
-
   // Flutter extension methods.
 
   // Invoke a flutter extension method, if the flutter extension is not
@@ -1140,6 +1144,9 @@ class Isolate extends ServiceObjectOwner {
       return result['value'];
     return 'unknown';
   }
+
+  @override
+  String toString() => 'Isolate $id';
 }
 
 class ServiceMap extends ServiceObject implements Map<String, dynamic> {