Remove all obsolete "// ignore:" (#27271)

diff --git a/packages/flutter_tools/lib/src/base/logger.dart b/packages/flutter_tools/lib/src/base/logger.dart
index 06b7807..ec08efb 100644
--- a/packages/flutter_tools/lib/src/base/logger.dart
+++ b/packages/flutter_tools/lib/src/base/logger.dart
@@ -467,6 +467,7 @@
   final Stopwatch _stopwatch = Stopwatch();
 
   @protected
+  @visibleForTesting
   bool get seemsSlow => timeout != null && _stopwatch.elapsed > timeout;
 
   @protected
diff --git a/packages/flutter_tools/lib/src/commands/daemon.dart b/packages/flutter_tools/lib/src/commands/daemon.dart
index b73f41f..0a261e0 100644
--- a/packages/flutter_tools/lib/src/commands/daemon.dart
+++ b/packages/flutter_tools/lib/src/commands/daemon.dart
@@ -187,9 +187,7 @@
   String toString() => name;
 
   void handleCommand(String command, dynamic id, Map<String, dynamic> args) {
-    // Remove 'new' once Google catches up to dev4.0 Dart SDK.
-    //ignore: unnecessary_new
-    new Future<dynamic>.sync(() {
+    Future<dynamic>.sync(() {
       if (_handlers.containsKey(command))
         return _handlers[command](args);
       throw 'command not understood: $name.$command';
diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index ed31c94..01d8c5c 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -163,7 +163,7 @@
       try {
         _xcodeSelectPath = processManager.runSync(<String>['/usr/bin/xcode-select', '--print-path']).stdout.trim();
       } on ProcessException {
-        // Ignore: return null below.
+        // Ignored, return null below.
       }
     }
     return _xcodeSelectPath;
diff --git a/packages/flutter_tools/lib/src/ios/xcodeproj.dart b/packages/flutter_tools/lib/src/ios/xcodeproj.dart
index e8e07fc..79a02ac 100644
--- a/packages/flutter_tools/lib/src/ios/xcodeproj.dart
+++ b/packages/flutter_tools/lib/src/ios/xcodeproj.dart
@@ -120,7 +120,7 @@
       _majorVersion = int.parse(components[0]);
       _minorVersion = components.length == 1 ? 0 : int.parse(components[1]);
     } on ProcessException {
-      // Ignore: leave values null.
+      // Ignored, leave values null.
     }
   }
 
diff --git a/packages/flutter_tools/lib/src/run_hot.dart b/packages/flutter_tools/lib/src/run_hot.dart
index df9627e..a3edabb 100644
--- a/packages/flutter_tools/lib/src/run_hot.dart
+++ b/packages/flutter_tools/lib/src/run_hot.dart
@@ -436,7 +436,7 @@
     for (FlutterView view in device.views)
       futures.add(view.runFromSource(entryUri, packagesUri, assetsDirectoryUri));
     final Completer<void> completer = Completer<void>();
-    Future.wait(futures).whenComplete(() { completer.complete(null); }); // ignore: unawaited_futures
+    Future.wait(futures).whenComplete(() { completer.complete(null); });
     return completer.future;
   }
 
diff --git a/packages/flutter_tools/lib/src/test/flutter_platform.dart b/packages/flutter_tools/lib/src/test/flutter_platform.dart
index e6f37e3..a7071e8 100644
--- a/packages/flutter_tools/lib/src/test/flutter_platform.dart
+++ b/packages/flutter_tools/lib/src/test/flutter_platform.dart
@@ -497,7 +497,7 @@
       // Callback can't throw since it's just setting a variable.
       controller.sink.done.whenComplete(() { // ignore: unawaited_futures
         controllerSinkClosed = true;
-      }); // ignore: unawaited_futures
+      });
 
       // Prepare our WebSocket server to talk to the engine subproces.
       final HttpServer server = await HttpServer.bind(host, port);
diff --git a/packages/flutter_tools/lib/src/usage.dart b/packages/flutter_tools/lib/src/usage.dart
index 7422d85..72d5857 100644
--- a/packages/flutter_tools/lib/src/usage.dart
+++ b/packages/flutter_tools/lib/src/usage.dart
@@ -35,9 +35,6 @@
     final FlutterVersion flutterVersion = FlutterVersion.instance;
     final String version = versionOverride ?? flutterVersion.getVersionString(redactUnknownBranches: true);
     _analytics = AnalyticsIO(_kFlutterUA, settingsName, version,
-        // Analyzer doesn't recognize that [Directory] objects match up due to a
-        // conditional import.
-        // ignore: argument_type_not_assignable
         documentDirectory: configDirOverride != null ? fs.directory(configDirOverride) : null);
 
     // Report a more detailed OS version string than package:usage does by default.
diff --git a/packages/flutter_tools/lib/src/vmservice.dart b/packages/flutter_tools/lib/src/vmservice.dart
index c733b52..2585c50 100644
--- a/packages/flutter_tools/lib/src/vmservice.dart
+++ b/packages/flutter_tools/lib/src/vmservice.dart
@@ -1384,7 +1384,7 @@
   Iterable<MapEntry<String, dynamic>> get entries => _map.entries;
   @override
   void updateAll(dynamic update(String key, dynamic value)) => _map.updateAll(update);
-  Map<RK, RV> retype<RK, RV>() => _map.cast<RK, RV>(); // ignore: annotate_overrides
+  Map<RK, RV> retype<RK, RV>() => _map.cast<RK, RV>();
   @override
   dynamic update(String key, dynamic update(dynamic value), {dynamic ifAbsent()}) => _map.update(key, update, ifAbsent: ifAbsent);
 }
diff --git a/packages/flutter_tools/test/base/logger_test.dart b/packages/flutter_tools/test/base/logger_test.dart
index ec61cff..07d5061 100644
--- a/packages/flutter_tools/test/base/logger_test.dart
+++ b/packages/flutter_tools/test/base/logger_test.dart
@@ -137,11 +137,11 @@
             timeout: const Duration(milliseconds: 10),
           )..start();
           doWhileAsync(time, () => ansiSpinner.ticks < 10); // one second
-          expect(ansiSpinner.seemsSlow, isFalse); // ignore: invalid_use_of_protected_member
+          expect(ansiSpinner.seemsSlow, isFalse);
           expect(outputStdout().join('\n'), isNot(contains('This is taking an unexpectedly long time.')));
           await tenMillisecondsLater;
           doWhileAsync(time, () => ansiSpinner.ticks < 30); // three seconds
-          expect(ansiSpinner.seemsSlow, isTrue); // ignore: invalid_use_of_protected_member
+          expect(ansiSpinner.seemsSlow, isTrue);
           expect(outputStdout().join('\n'), contains('This is taking an unexpectedly long time.'));
           ansiSpinner.stop();
           expect(outputStdout().join('\n'), isNot(contains('(!)')));
@@ -231,12 +231,12 @@
         await FakeAsync().run((FakeAsync time) async {
           ansiStatus.start();
           doWhileAsync(time, () => ansiStatus.ticks < 10); // one second
-          expect(ansiStatus.seemsSlow, isFalse); // ignore: invalid_use_of_protected_member
+          expect(ansiStatus.seemsSlow, isFalse);
           expect(outputStdout().join('\n'), isNot(contains('This is taking an unexpectedly long time.')));
           expect(outputStdout().join('\n'), isNot(contains('(!)')));
           await tenMillisecondsLater;
           doWhileAsync(time, () => ansiStatus.ticks < 30); // three seconds
-          expect(ansiStatus.seemsSlow, isTrue); // ignore: invalid_use_of_protected_member
+          expect(ansiStatus.seemsSlow, isTrue);
           expect(outputStdout().join('\n'), contains('This is taking an unexpectedly long time.'));
           ansiStatus.stop();
           expect(outputStdout().join('\n'), contains('(!)'));