Remove "unnecessary" imports. (#75637)

packages/flutter/test/rendering/aspect_ratio_test.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/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 

packages/flutter/test/rendering/baseline_test.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/material.dart';
 import 'package:flutter/rendering.dart';
 import '../flutter_test_alternative.dart';
 

packages/flutter/test/rendering/editable_gesture_test.dart

@@ -5,11 +5,8 @@
 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 '../flutter_test_alternative.dart' show Fake;
-
 void main() {
   setUp(() => _GestureBindingSpy());
 

packages/flutter/test/rendering/independent_layout_test.dart

@@ -4,7 +4,6 @@
 
 import 'dart:ui' as ui show window;
 
-import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import '../flutter_test_alternative.dart';
 

packages/flutter/test/rendering/limited_box_test.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/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 

packages/flutter/test/rendering/mouse_tracking_cursor_test.dart

@@ -5,7 +5,6 @@
 import 'dart:ui' as ui;
 import 'dart:ui' show PointerChange;
 
-import 'package:flutter/cupertino.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/services.dart';

packages/flutter/test/rendering/mouse_tracking_test.dart

@@ -5,11 +5,9 @@
 import 'dart:ui' as ui;
 import 'dart:ui' show PointerChange;
 
-import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/gestures.dart';
-import 'package:vector_math/vector_math_64.dart' show Matrix4;
 
 import '../flutter_test_alternative.dart';
 import './mouse_tracking_test_utils.dart';

packages/flutter/test/rendering/mouse_tracking_test_utils.dart

@@ -4,13 +4,11 @@
 
 import 'dart:ui' as ui;
 
-import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
-import 'package:vector_math/vector_math_64.dart' show Matrix4;
 
 class _TestHitTester extends RenderBox {
   _TestHitTester(this.hitTestOverride);

packages/flutter/test/rendering/mutations_test.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/material.dart';
 import 'package:flutter/rendering.dart';
 import '../flutter_test_alternative.dart';
 

packages/flutter/test/rendering/non_render_object_root_test.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/material.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import '../flutter_test_alternative.dart';

packages/flutter/test/rendering/offstage_test.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/material.dart';
 import 'package:flutter/rendering.dart';
 import '../flutter_test_alternative.dart';
 

packages/flutter/test/rendering/overflow_test.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/material.dart';
 import 'package:flutter/rendering.dart';
 import '../flutter_test_alternative.dart';
 

packages/flutter/test/rendering/paint_error_test.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui';
-
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';

packages/flutter/test/rendering/paragraph_test.dart

@@ -7,7 +7,6 @@ import 'dart:ui' as ui show TextBox;
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'rendering_tester.dart';

packages/flutter/test/rendering/platform_view_test.dart

@@ -8,7 +8,6 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:flutter/material.dart';
 import '../services/fake_platform_views.dart';
 import 'rendering_tester.dart';
 

packages/flutter/test/rendering/proxy_sliver_test.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/animation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 import '../flutter_test_alternative.dart';