Fixes a cursor offset mistake for Material on iOS (#27851)

* Fixes offset and unblocks roll

packages/flutter/lib/src/cupertino/button.dart

@@ -110,11 +110,6 @@ class CupertinoButton extends StatefulWidget {
   /// Defaults to round corners of 8 logical pixels.
   final BorderRadius borderRadius;
 
-  /// The shape of the button.
-  ///
-  /// Defaults to a super ellipse with
-//  final ShapeBorder shape;
-
   final bool _filled;
 
   /// Whether the button is enabled or disabled. Buttons are disabled by default. To

packages/flutter/lib/src/material/text_field.dart

@@ -778,7 +778,7 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
         //
         // This value is in device pixels, not logical pixels as is typically used
         // throughout the codebase.
-        const int _iOSHorizontalOffset = 2;
+        const int _iOSHorizontalOffset = -2;
         cursorOffset = Offset(_iOSHorizontalOffset / MediaQuery.of(context).devicePixelRatio, 0);
         break;
 

packages/flutter/test/material/text_field_test.dart

@@ -4326,14 +4326,14 @@ void main() {
 
       expect(lastCharEndpoint.length, 1);
       // The last character is now on screen.
-      expect(lastCharEndpoint[0].point.dx, moreOrLessEquals(797.3333129882812));
+      expect(lastCharEndpoint[0].point.dx, moreOrLessEquals(798.6666870117188));
 
       final List<TextSelectionPoint> firstCharEndpoint = renderEditable.getEndpointsForSelection(
         const TextSelection.collapsed(offset: 0), // First character's position.
       );
       expect(firstCharEndpoint.length, 1);
       // The first character is now offscreen to the left.
-      expect(firstCharEndpoint[0].point.dx, moreOrLessEquals(-258.66668701171875));
+      expect(firstCharEndpoint[0].point.dx, moreOrLessEquals(-257.33331298828125));
   });
 
   testWidgets(

packages/flutter/test/widgets/editable_text_cursor_test.dart

@@ -512,7 +512,9 @@ void main() {
     expect(controller.selection.baseOffset, text.length);
   });
 
-  testWidgets('Floating cursor is painted', (WidgetTester tester) async {
+  testWidgets('Floating cursor is painted on iOS', (WidgetTester tester) async {
+    final TextEditingController controller = TextEditingController();
+    const TextStyle textStyle = TextStyle();
     const String text = 'hello world this is fun and cool and awesome!';
     controller.text = text;
     final FocusNode focusNode = FocusNode();
@@ -544,7 +546,7 @@ void main() {
     editableTextState.updateFloatingCursor(
       RawFloatingCursorPoint(
         state: FloatingCursorDragState.Update,
-        offset: const Offset(20, 20),
+        offset: const Offset(20, 20)
       ),
     );
     await tester.pump();
@@ -552,41 +554,45 @@ void main() {
     expect(editable, paints
       ..rrect(
         rrect: RRect.fromRectAndRadius(
-          Rect.fromLTRB(464.6666564941406, 2.0833332538604736, 466.6666564941406, 14.083333015441895),
-          const Radius.circular(2.0),
+          Rect.fromLTRB(463.3333435058594, 2.0833332538604736, 465.3333435058594, 14.083333015441895),
+          const Radius.circular(2.0)
         ),
-        color: const Color(0xff8e8e93))
+        color: const Color(0xff8e8e93),
+      )
       ..rrect(
         rrect: RRect.fromRectAndRadius(
-          Rect.fromLTRB(465.1666564941406, 1.0833336114883423, 468.1666564941406, 15.083333969116211),
+          Rect.fromLTRB(463.8333435058594, 1.0833336114883423, 466.8333435058594, 15.083333969116211),
           const Radius.circular(1.0),
         ),
-        color: const Color(0xbf2196f3))
+        color: const Color(0xbf2196f3),
+      )
     );
 
     // Moves the cursor right a few characters.
     editableTextState.updateFloatingCursor(
-        RawFloatingCursorPoint(
-          state: FloatingCursorDragState.Update,
-          offset: const Offset(-250, 20)));
+      RawFloatingCursorPoint(
+        state: FloatingCursorDragState.Update,
+        offset: const Offset(-250, 20)
+      ),
+    );
 
     expect(find.byType(EditableText), paints
       ..rrect(
         rrect: RRect.fromRectAndRadius(
-          Rect.fromLTRB(192.6666717529297, 2.0833332538604736, 194.6666717529297, 14.083333015441895),
-          const Radius.circular(2.0),
+          Rect.fromLTRB(191.3333282470703, 2.0833332538604736, 193.3333282470703, 14.083333015441895),
+          const Radius.circular(2.0)
         ),
-        color: const Color(0xff8e8e93))
+        color: const Color(0xff8e8e93)
+      )
       ..rrect(
         rrect: RRect.fromRectAndRadius(
-          Rect.fromLTRB(195.16665649414062, 1.0833336114883423, 198.16665649414062, 15.083333969116211),
-          const Radius.circular(1.0),
-        ),
-        color: const Color(0xbf2196f3))
+          Rect.fromLTRB(193.83334350585938, 1.0833336114883423, 196.83334350585938, 15.083333969116211),
+          const Radius.circular(1.0)),
+        color: const Color(0xbf2196f3),
+      )
     );
 
     editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.End));
-
     await tester.pumpAndSettle();
   });
 }