format parameter list (#27261)

diff --git a/packages/flutter_tools/lib/src/commands/attach.dart b/packages/flutter_tools/lib/src/commands/attach.dart
index 81cfd2b..6f4dc41 100644
--- a/packages/flutter_tools/lib/src/commands/attach.dart
+++ b/packages/flutter_tools/lib/src/commands/attach.dart
@@ -275,18 +275,19 @@
 }
 
 class HotRunnerFactory {
-  HotRunner build(List<FlutterDevice> devices, {
-      String target,
-      DebuggingOptions debuggingOptions,
-      bool usesTerminalUI = true,
-      bool benchmarkMode = false,
-      File applicationBinary,
-      bool hostIsIde = false,
-      String projectRootPath,
-      String packagesFilePath,
-      String dillOutputPath,
-      bool stayResident = true,
-      bool ipv6 = false,
+  HotRunner build(
+    List<FlutterDevice> devices, {
+    String target,
+    DebuggingOptions debuggingOptions,
+    bool usesTerminalUI = true,
+    bool benchmarkMode = false,
+    File applicationBinary,
+    bool hostIsIde = false,
+    String projectRootPath,
+    String packagesFilePath,
+    String dillOutputPath,
+    bool stayResident = true,
+    bool ipv6 = false,
   }) => HotRunner(
     devices,
     target: target,
diff --git a/packages/flutter_tools/lib/src/commands/create.dart b/packages/flutter_tools/lib/src/commands/create.dart
index 2a13c4c..53fdd7b 100644
--- a/packages/flutter_tools/lib/src/commands/create.dart
+++ b/packages/flutter_tools/lib/src/commands/create.dart
@@ -395,7 +395,7 @@
     return null;
   }
 
-  Future<int> _generateModule(Directory directory, Map<String, dynamic> templateContext, {bool overwrite = false}) async {
+  Future<int> _generateModule(Directory directory, Map<String, dynamic> templateContext, { bool overwrite = false }) async {
     int generatedCount = 0;
     final String description = argResults.wasParsed('description')
         ? argResults['description']
@@ -414,7 +414,7 @@
     return generatedCount;
   }
 
-  Future<int> _generatePackage(Directory directory, Map<String, dynamic> templateContext, {bool overwrite = false}) async {
+  Future<int> _generatePackage(Directory directory, Map<String, dynamic> templateContext, { bool overwrite = false }) async {
     int generatedCount = 0;
     final String description = argResults.wasParsed('description')
         ? argResults['description']
@@ -431,7 +431,7 @@
     return generatedCount;
   }
 
-  Future<int> _generatePlugin(Directory directory, Map<String, dynamic> templateContext, {bool overwrite = false}) async {
+  Future<int> _generatePlugin(Directory directory, Map<String, dynamic> templateContext, { bool overwrite = false }) async {
     int generatedCount = 0;
     final String description = argResults.wasParsed('description')
         ? argResults['description']
@@ -463,7 +463,7 @@
     return generatedCount;
   }
 
-  Future<int> _generateApp(Directory directory, Map<String, dynamic> templateContext, {bool overwrite = false}) async {
+  Future<int> _generateApp(Directory directory, Map<String, dynamic> templateContext, { bool overwrite = false }) async {
     int generatedCount = 0;
     generatedCount += _renderTemplate('app', directory, templateContext, overwrite: overwrite);
     final FlutterProject project = await FlutterProject.fromDirectory(directory);
@@ -536,7 +536,7 @@
     };
   }
 
-  int _renderTemplate(String templateName, Directory directory, Map<String, dynamic> context, {bool overwrite = false}) {
+  int _renderTemplate(String templateName, Directory directory, Map<String, dynamic> context, { bool overwrite = false }) {
     final Template template = Template.fromName(templateName);
     return template.render(directory, context, overwriteExisting: overwrite);
   }
diff --git a/packages/flutter_tools/lib/src/commands/daemon.dart b/packages/flutter_tools/lib/src/commands/daemon.dart
index a632028..3e522a8 100644
--- a/packages/flutter_tools/lib/src/commands/daemon.dart
+++ b/packages/flutter_tools/lib/src/commands/daemon.dart
@@ -161,7 +161,7 @@
 
   void _send(Map<String, dynamic> map) => sendCommand(map);
 
-  void shutdown({dynamic error}) {
+  void shutdown({ dynamic error }) {
     _commandSubscription?.cancel();
     for (Domain domain in _domainMap.values)
       domain.dispose();
@@ -210,7 +210,7 @@
     });
   }
 
-  void sendEvent(String name, [dynamic args]) {
+  void sendEvent(String name, [ dynamic args ]) {
     final Map<String, dynamic> map = <String, dynamic>{ 'event': name };
     if (args != null)
       map['params'] = _toJsonable(args);
@@ -333,8 +333,12 @@
   final List<AppInstance> _apps = <AppInstance>[];
 
   Future<AppInstance> startApp(
-    Device device, String projectDirectory, String target, String route,
-    DebuggingOptions options, bool enableHotReload, {
+    Device device,
+    String projectDirectory,
+    String target,
+    String route,
+    DebuggingOptions options,
+    bool enableHotReload, {
     File applicationBinary,
     @required bool trackWidgetCreation,
     String projectRootPath,
@@ -405,13 +409,14 @@
   }
 
   Future<AppInstance> launch(
-      ResidentRunner runner,
-      _RunOrAttach runOrAttach,
-      Device device,
-      String projectDirectory,
-      bool enableHotReload,
-      Directory cwd,
-      LaunchMode launchMode) async {
+    ResidentRunner runner,
+    _RunOrAttach runOrAttach,
+    Device device,
+    String projectDirectory,
+    bool enableHotReload,
+    Directory cwd,
+    LaunchMode launchMode,
+  ) async {
     final AppInstance app = AppInstance(_getNewAppId(),
         runner: runner, logToStdout: daemon.logToStdout);
     _apps.add(app);
@@ -562,7 +567,7 @@
     return _apps.firstWhere((AppInstance app) => app.id == id, orElse: () => null);
   }
 
-  void _sendAppEvent(AppInstance app, String name, [Map<String, dynamic> args]) {
+  void _sendAppEvent(AppInstance app, String name, [ Map<String, dynamic> args ]) {
     final Map<String, dynamic> eventArgs = <String, dynamic> { 'appId': app.id };
     if (args != null)
       eventArgs.addAll(args);
@@ -620,7 +625,7 @@
 
   /// Return a list of the current devices, with each device represented as a map
   /// of properties (id, name, platform, ...).
-  Future<List<Map<String, dynamic>>> getDevices([Map<String, dynamic> args]) async {
+  Future<List<Map<String, dynamic>>> getDevices([ Map<String, dynamic> args ]) async {
     final List<Map<String, dynamic>> devicesInfo = <Map<String, dynamic>>[];
 
     for (PollingDeviceDiscovery discoverer in _discoverers) {
@@ -761,27 +766,27 @@
 
   @override
   void printError(
-      String message, {
-      StackTrace stackTrace,
-      bool emphasis = false,
-      TerminalColor color,
-      int indent,
-      int hangingIndent,
-      bool wrap,
-    }) {
+    String message, {
+    StackTrace stackTrace,
+    bool emphasis = false,
+    TerminalColor color,
+    int indent,
+    int hangingIndent,
+    bool wrap,
+  }) {
     _messageController.add(LogMessage('error', message, stackTrace));
   }
 
   @override
   void printStatus(
-      String message, {
-      bool emphasis = false,
-      TerminalColor color,
-      bool newline = true,
-      int indent,
-      int hangingIndent,
-      bool wrap,
-    }) {
+    String message, {
+    bool emphasis = false,
+    TerminalColor color,
+    bool newline = true,
+    int indent,
+    int hangingIndent,
+    bool wrap,
+  }) {
     _messageController.add(LogMessage('status', message));
   }
 
@@ -851,7 +856,7 @@
 
   EmulatorManager emulators = EmulatorManager();
 
-  Future<List<Map<String, dynamic>>> getEmulators([Map<String, dynamic> args]) async {
+  Future<List<Map<String, dynamic>>> getEmulators([ Map<String, dynamic> args ]) async {
     final List<Emulator> list = await emulators.getAllAvailableEmulators();
     return list.map<Map<String, dynamic>>(_emulatorToMap).toList();
   }
@@ -898,14 +903,14 @@
 
   @override
   void printError(
-      String message, {
-      StackTrace stackTrace,
-      bool emphasis,
-      TerminalColor color,
-      int indent,
-      int hangingIndent,
-      bool wrap,
-    }) {
+    String message, {
+    StackTrace stackTrace,
+    bool emphasis,
+    TerminalColor color,
+    int indent,
+    int hangingIndent,
+    bool wrap,
+  }) {
     if (parent != null) {
       parent.printError(
         message,
@@ -933,14 +938,14 @@
 
   @override
   void printStatus(
-      String message, {
-      bool emphasis = false,
-      TerminalColor color,
-      bool newline = true,
-      int indent,
-      int hangingIndent,
-      bool wrap,
-    }) {
+    String message, {
+    bool emphasis = false,
+    TerminalColor color,
+    bool newline = true,
+    int indent,
+    int hangingIndent,
+    bool wrap,
+  }) {
     if (parent != null) {
       parent.printStatus(
         message,
diff --git a/packages/flutter_tools/lib/src/commands/emulators.dart b/packages/flutter_tools/lib/src/commands/emulators.dart
index 4821519..471a26d 100644
--- a/packages/flutter_tools/lib/src/commands/emulators.dart
+++ b/packages/flutter_tools/lib/src/commands/emulators.dart
@@ -83,7 +83,7 @@
     }
   }
 
-  Future<void> _createEmulator({String name}) async {
+  Future<void> _createEmulator({ String name }) async {
     final CreateEmulatorResult createResult =
         await emulatorManager.createEmulator(name: name);
 
@@ -118,8 +118,10 @@
     _printAdditionalInfo(showCreateInstruction: true, showRunInstruction: true);
   }
 
-  void _printAdditionalInfo({ bool showRunInstruction = false,
-      bool showCreateInstruction = false }) {
+  void _printAdditionalInfo({
+    bool showRunInstruction = false,
+    bool showCreateInstruction = false,
+  }) {
     printStatus('');
     if (showRunInstruction) {
       printStatus(
diff --git a/packages/flutter_tools/lib/src/commands/ide_config.dart b/packages/flutter_tools/lib/src/commands/ide_config.dart
index f153b3b..e977779 100644
--- a/packages/flutter_tools/lib/src/commands/ide_config.dart
+++ b/packages/flutter_tools/lib/src/commands/ide_config.dart
@@ -266,7 +266,7 @@
 
 /// Return null if the flutter root directory is a valid destination. Return a
 /// validation message if we should disallow the directory.
-String _validateFlutterDir(String dirPath, {String flutterRoot}) {
+String _validateFlutterDir(String dirPath, { String flutterRoot }) {
   final FileSystemEntityType type = fs.typeSync(dirPath);
 
   if (type != FileSystemEntityType.notFound) {
diff --git a/packages/flutter_tools/lib/src/commands/update_packages.dart b/packages/flutter_tools/lib/src/commands/update_packages.dart
index 5f7c5d8..cfd678a 100644
--- a/packages/flutter_tools/lib/src/commands/update_packages.dart
+++ b/packages/flutter_tools/lib/src/commands/update_packages.dart
@@ -1187,7 +1187,8 @@
 
   /// The transitive closure of all the dependencies for the given package,
   /// excluding any listen in `seen`.
-  Iterable<String> getTransitiveDependenciesFor(String package, {
+  Iterable<String> getTransitiveDependenciesFor(
+    String package, {
     @required Set<String> seen,
     @required Set<String> exclude,
   }) sync* {