Remove "unnecessary" imports. (#74385)

dev/manual_tests/lib/actions.dart

@@ -8,7 +8,6 @@ import 'dart:io';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter/widgets.dart';
 
 void main() {
   runApp(const MaterialApp(

dev/manual_tests/lib/card_collection.dart

@@ -5,7 +5,6 @@
 import 'dart:math';
 
 import 'package:flutter/material.dart';
-import 'package:flutter/rendering.dart' show debugDumpRenderTree;
 
 class CardModel {
   CardModel(this.value, this.height) {

dev/manual_tests/lib/color_testing_demo.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/material.dart';
-import 'package:flutter/rendering.dart';
 
 class ColorTestingDemo extends StatelessWidget {
   const ColorTestingDemo({ Key key }) : super(key: key);

dev/manual_tests/lib/density.dart

@@ -2,10 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/scheduler.dart' show timeDilation;
 import 'package:flutter/material.dart';
-import 'package:flutter/rendering.dart';
 
 final Map<int, Color> m2SwatchColors = <int, Color>{
   50: const Color(0xfff2e7fe),

dev/manual_tests/lib/drag_and_drop.dart

@@ -4,7 +4,6 @@
 
 import 'dart:math' as math;
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 class ExampleDragTarget extends StatefulWidget {

dev/manual_tests/lib/focus.dart

@@ -2,10 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter/widgets.dart';
 
 void main() {
   runApp(const MaterialApp(

dev/manual_tests/lib/hover.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 void main() {

dev/manual_tests/lib/material_arc.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 

dev/manual_tests/lib/overlay_geometry.dart

@@ -2,10 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
-import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/rendering.dart';
 
 class CardModel {
   CardModel(this.value, this.height, this.color);

dev/manual_tests/lib/page_view.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 class CardModel {

dev/manual_tests/lib/raw_keyboard.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 

dev/manual_tests/lib/text.dart

@@ -6,7 +6,6 @@ import 'dart:math' as math;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 
 int seed = 0;

dev/manual_tests/test/color_testing_demo_test.dart

@@ -4,7 +4,6 @@
 
 import 'dart:io';
 
-import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:manual_tests/color_testing_demo.dart' as color_testing_demo;