Revert "Fix text field selection toolbar under Opacity (#31097)" (#31800)

packages/flutter/lib/src/rendering/layer.dart

@@ -1282,13 +1282,6 @@ class OpacityLayer extends ContainerLayer {
     }
   }
 
-  @override
-  void applyTransform(Layer child, Matrix4 transform) {
-    assert(child != null);
-    assert(transform != null);
-    transform.translate(offset.dx, offset.dy);
-  }
-
   @override
   ui.EngineLayer addToScene(ui.SceneBuilder builder, [ Offset layerOffset = Offset.zero ]) {
     bool enabled = firstChild != null;  // don't add this layer if there's no child

packages/flutter/test/material/text_field_test.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:io';
 import 'dart:math' as math;
 import 'dart:ui' as ui show window;
 
@@ -381,58 +380,6 @@ void main() {
     expect(textField.cursorRadius, const Radius.circular(3.0));
   });
 
-  testWidgets('text field selection toolbar renders correctly inside opacity', (WidgetTester tester) async {
-    await tester.pumpWidget(
-      MaterialApp(
-        home: Scaffold(
-          body: Center(
-            child: Container(
-              width: 100,
-              height: 100,
-              child: const Opacity(
-                opacity: 0.5,
-                child: TextField(
-                  decoration: InputDecoration(hintText: 'Placeholder'),
-                ),
-              ),
-            ),
-          ),
-        ),
-      ),
-    );
-
-    await tester.showKeyboard(find.byType(TextField));
-
-    const String testValue = 'A B C';
-    tester.testTextInput.updateEditingValue(
-        const TextEditingValue(
-          text: testValue
-        )
-    );
-    await tester.pump();
-
-    // The selectWordsInRange with SelectionChangedCause.tap seems to be needed to show the toolbar.
-    // (This is true even if we provide selection parameter to the TextEditingValue above.)
-    final EditableTextState state = tester.state<EditableTextState>(find.byType(EditableText));
-    state.renderEditable.selectWordsInRange(from: const Offset(0, 0), cause: SelectionChangedCause.tap);
-
-    expect(state.showToolbar(), true);
-
-    // This is needed for the AnimatedOpacity to turn from 0 to 1 so the toolbar is visible.
-    await tester.pump();
-    await tester.pump(const Duration(seconds: 1));
-
-    // Sanity check that the toolbar widget exists.
-    expect(find.text('PASTE'), findsOneWidget);
-
-    await expectLater(
-      // The toolbar exists in the Overlay above the MaterialApp.
-      find.byType(Overlay),
-      matchesGoldenFile('text_field_opacity_test.0.0.png'),
-      skip: !Platform.isLinux,
-    );
-  });
-
   // TODO(hansmuller): restore these tests after the fix for #24876 has landed.
   /*
   testWidgets('cursor layout has correct width', (WidgetTester tester) async {