Allow skipping chrome launch with --no-web-browser-launch (#40627)

packages/flutter_tools/lib/src/base/logger.dart

@@ -146,6 +146,14 @@ abstract class Logger {
     bool multilineOutput = false,
     int progressIndicatorPadding = kDefaultStatusPadding,
   });
+
+  /// Send a progress notification that is instant.
+  ///
+  /// Only surfaces a value in machine modes, Loggers may ignore this message in
+  /// non-machine modes. Like [startProgress] but with a single event.
+  void sendNotification(String message, {
+    String progressId,
+  });
 }
 
 class StdoutLogger extends Logger {
@@ -250,6 +258,9 @@ class StdoutLogger extends Logger {
   void _clearStatus() {
     _status = null;
   }
+
+  @override
+  void sendNotification(String message, {String progressId}) { }
 }
 
 /// A [StdoutLogger] which replaces Unicode characters that cannot be printed to
@@ -341,6 +352,9 @@ class BufferLogger extends Logger {
     _status.clear();
     _trace.clear();
   }
+
+  @override
+  void sendNotification(String message, {String progressId}) { }
 }
 
 class VerboseLogger extends Logger {
@@ -453,6 +467,9 @@ class VerboseLogger extends Logger {
       parent.printStatus(prefix + indentMessage);
     }
   }
+
+  @override
+  void sendNotification(String message, {String progressId}) { }
 }
 
 enum _LogType { error, status, trace }

packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart

@@ -177,7 +177,7 @@ class ResidentWebRunner extends ResidentRunner {
         'uri': _webFs.uri
       });
       if (supportsServiceProtocol) {
-        _debugConnection = await _webFs.runAndDebug();
+        _debugConnection = await _webFs.runAndDebug(debuggingOptions);
         unawaited(_debugConnection.onDone.whenComplete(exit));
       }
     } catch (err, stackTrace) {

packages/flutter_tools/lib/src/build_runner/web_fs.dart

@@ -30,6 +30,7 @@ import '../build_info.dart';
 import '../bundle.dart';
 import '../cache.dart';
 import '../dart/package_map.dart';
+import '../device.dart';
 import '../globals.dart';
 import '../platform_plugins.dart';
 import '../plugins.dart';
@@ -107,15 +108,19 @@ class WebFs {
     await _connectedApps?.cancel();
   }
 
+  Future<DebugConnection> _cachedExtensionFuture;
+
   /// Retrieve the [DebugConnection] for the current application
-  Future<DebugConnection> runAndDebug() {
+  Future<DebugConnection> runAndDebug(DebuggingOptions debuggingOptions) {
     final Completer<DebugConnection> firstConnection = Completer<DebugConnection>();
     _connectedApps = _dwds.connectedApps.listen((AppConnection appConnection) async {
-      appConnection.runMain();
-      final DebugConnection debugConnection = await _dwds.debugConnection(appConnection);
+      final DebugConnection debugConnection = debuggingOptions.browserLaunch
+        ? await _dwds.debugConnection(appConnection)
+        : await (_cachedExtensionFuture ??= _dwds.extensionDebugConnections.stream.first);
       if (!firstConnection.isCompleted) {
         firstConnection.complete(debugConnection);
       }
+      appConnection.runMain();
     });
     return firstConnection.future;
   }

packages/flutter_tools/lib/src/commands/daemon.dart

@@ -895,6 +895,9 @@ class NotifyingLogger extends Logger {
   void dispose() {
     _messageController.close();
   }
+
+  @override
+  void sendNotification(String message, {String progressId}) { }
 }
 
 /// A running application, started by this daemon.
@@ -1105,6 +1108,16 @@ class _AppRunLogger extends Logger {
       domain._sendAppEvent(app, 'progress', event);
     }
   }
+
+  @override
+  void sendNotification(String message, {String progressId}) {
+    final int id = _nextProgressId++;
+    _sendProgressEvent(<String, dynamic>{
+      'id': id.toString(),
+      'progressId': progressId,
+      'finished': true,
+    });
+  }
 }
 
 class LogMessage {

packages/flutter_tools/lib/src/commands/run.dart

@@ -306,6 +306,7 @@ class RunCommand extends RunCommandBase {
         initializePlatform: argResults['web-initialize-platform'],
         hostname: featureFlags.isWebEnabled ? argResults['web-hostname'] : '',
         port: featureFlags.isWebEnabled ? argResults['web-port'] : '',
+        browserLaunch: featureFlags.isWebEnabled ? argResults['web-browser-launch'] : null,
       );
     }
   }

packages/flutter_tools/lib/src/device.dart

@@ -492,6 +492,7 @@ class DebuggingOptions {
     this.initializePlatform = true,
     this.hostname,
     this.port,
+    this.browserLaunch = true,
    }) : debuggingEnabled = true;
 
   DebuggingOptions.disabled(this.buildInfo, { this.initializePlatform = true, this.port, this.hostname })
@@ -506,7 +507,8 @@ class DebuggingOptions {
       traceSystrace = false,
       dumpSkpOnShaderCompilation = false,
       verboseSystemLogs = false,
-      observatoryPort = null;
+      observatoryPort = null,
+      browserLaunch = true;
 
   final bool debuggingEnabled;
 
@@ -526,6 +528,7 @@ class DebuggingOptions {
   final int observatoryPort;
   final String port;
   final String hostname;
+  final bool browserLaunch;
 
   bool get hasObservatoryPort => observatoryPort != null;
 }

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -146,6 +146,14 @@ abstract class FlutterCommand extends Command<void> {
         'will select a random open port on the host.',
       hide: hide,
     );
+    argParser.addFlag('web-browser-launch',
+      defaultsTo: true,
+      negatable: true,
+      help: 'Whether to automatically launch browsers for web devices '
+        'that do so. Setting this to true allows using the Dart debug extension '
+        'on Chrome and other browsers which support extensions.',
+      hide: hide,
+    );
   }
 
   void usesTargetOption() {

packages/flutter_tools/lib/src/web/web_device.dart

@@ -131,7 +131,13 @@ class ChromeDevice extends Device {
   }) async {
     // See [ResidentWebRunner.run] in flutter_tools/lib/src/resident_web_runner.dart
     // for the web initialization and server logic.
-    _chrome = await chromeLauncher.launch(platformArgs['uri']);
+    final String url = platformArgs['uri'];
+    if (debuggingOptions.browserLaunch) {
+      _chrome = await chromeLauncher.launch(url);
+    } else {
+      printStatus('Waiting for connection from Dart debug extension at $url', emphasis: true);
+      logger.sendNotification(url, progressId: 'debugExtension');
+    }
     return LaunchResult.succeeded(observatoryUri: null);
   }
 
@@ -240,6 +246,7 @@ class WebServerDevice extends Device {
   }) async {
     final String url = platformArgs['uri'];
     printStatus('$mainPath is being served at $url', emphasis: true);
+    logger.sendNotification(url, progressId: 'debugExtension');
     return LaunchResult.succeeded(observatoryUri: null);
   }
 

packages/flutter_tools/test/general.shard/commands/attach_test.dart

@@ -539,6 +539,9 @@ class StreamLogger extends Logger {
   }
 
   Stream<String> get stream => _controller.stream;
+
+  @override
+  void sendNotification(String message, {String progressId}) { }
 }
 
 class LoggerInterrupted implements Exception {

packages/flutter_tools/test/general.shard/resident_web_runner_cold_test.dart

@@ -56,7 +56,7 @@ void main() {
     fs.file('pubspec.yaml').createSync();
     fs.file(fs.path.join('lib', 'main.dart')).createSync(recursive: true);
     fs.file(fs.path.join('web', 'index.html')).createSync(recursive: true);
-    when(mockWebFs.runAndDebug()).thenThrow(StateError('debugging not supported'));
+    when(mockWebFs.runAndDebug(any)).thenThrow(StateError('debugging not supported'));
   }
 
   test('Can successfully run and connect without vmservice', () => testbed.run(() async {

packages/flutter_tools/test/general.shard/resident_web_runner_test.dart

@@ -65,7 +65,7 @@ void main() {
     fs.file('pubspec.yaml').createSync();
     fs.file(fs.path.join('lib', 'main.dart')).createSync(recursive: true);
     fs.file(fs.path.join('web', 'index.html')).createSync(recursive: true);
-    when(mockWebFs.runAndDebug()).thenAnswer((Invocation _) async {
+    when(mockWebFs.runAndDebug(any)).thenAnswer((Invocation _) async {
       return mockDebugConnection;
     });
     when(mockWebFs.recompile()).thenAnswer((Invocation _) {