Remove "unnecessary" imports from packages/ (#89795)

packages/flutter/lib/src/services/binding.dart

@@ -6,7 +6,6 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
-import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/foundation.dart';

packages/flutter/test/painting/box_painter_test.dart

@@ -7,8 +7,6 @@
 @Tags(<String>['reduced-test-set'])
 
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
-import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {

packages/flutter/test/painting/paint_image_test.dart

@@ -6,7 +6,6 @@ import 'dart:ui' as ui;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 class TestCanvas implements Canvas {

packages/flutter/test/rendering/editable_test.dart

@@ -12,7 +12,6 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:meta/meta.dart';
 

packages/flutter/test/widgets/animated_cross_fade_test.dart

@@ -4,7 +4,6 @@
 
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
-import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {

packages/flutter/test/widgets/overscroll_stretch_indicator_test.dart

@@ -6,7 +6,6 @@
 // machines.
 @Tags(<String>['reduced-test-set'])
 
-import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 

packages/flutter_test/lib/src/_matchers_io.dart

@@ -6,7 +6,6 @@ import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/rendering.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:test_api/src/expect/async_matcher.dart'; // ignore: implementation_imports
 import 'package:test_api/test_api.dart'; // ignore: deprecated_member_use

packages/flutter_test/lib/src/event_simulation.dart

@@ -6,14 +6,10 @@ import 'dart:async';
 import 'dart:io';
 import 'dart:ui' as ui;
 
-import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import 'binding.dart';
-import 'test_async_utils.dart';
-
 // A tuple of `key` and `location` from Web's `KeyboardEvent` class.
 //
 // See [RawKeyEventDataWeb]'s `key` and `location` fields for details.

packages/flutter_tools/test/commands.shard/hermetic/custom_devices.dart

@@ -24,12 +24,10 @@ import 'package:flutter_tools/src/custom_devices/custom_device_config.dart';
 import 'package:flutter_tools/src/custom_devices/custom_devices_config.dart';
 import 'package:flutter_tools/src/runner/flutter_command_runner.dart';
 import 'package:meta/meta.dart';
-import 'package:process/process.dart';
 
 import '../../src/common.dart';
 import '../../src/context.dart';
 import '../../src/fakes.dart';
-import '../../src/test_flutter_command_runner.dart';
 
 const String linuxFlutterRoot = '/flutter';
 const String windowsFlutterRoot = r'C:\flutter';

packages/flutter_tools/test/general.shard/drive/web_driver_service_test.dart

@@ -23,7 +23,6 @@ import 'package:webdriver/sync_io.dart' as sync_io;
 
 import '../../src/common.dart';
 import '../../src/context.dart';
-import '../../src/fake_vm_services.dart';
 
 void main() {
   testWithoutContext('getDesiredCapabilities Chrome with headless on', () {

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

@@ -5,7 +5,6 @@
 // @dart = 2.8
 
 import 'dart:async';
-import 'dart:io';
 
 import 'package:dds/dds.dart' as dds;
 import 'package:file/memory.dart';