Revert "Re-add deprecated method for plugin migration compatibility. (#34006)" (#34022)

This reverts commit 160a5680.

packages/flutter/lib/src/painting/inline_span.dart

@@ -8,7 +8,6 @@ import 'package:flutter/foundation.dart';
 
 import 'basic_types.dart';
 import 'text_painter.dart';
-import 'text_span.dart';
 import 'text_style.dart';
 
 /// Mutable wrapper of an integer that can be passed by reference to track a
@@ -104,15 +103,6 @@ abstract class InlineSpan extends DiagnosticableTree {
   /// [Paragraph] objects can be drawn on [Canvas] objects.
   void build(ui.ParagraphBuilder builder, { double textScaleFactor = 1.0, List<PlaceholderDimensions> dimensions });
 
-  // TODO(garyq): Remove this after next stable release.
-  /// Walks this [TextSpan] and any descendants in pre-order and calls `visitor`
-  /// for each span that has content.
-  ///
-  /// When `visitor` returns true, the walk will continue. When `visitor` returns
-  /// false, then the walk will end.
-  @Deprecated('Use to visitChildren instead')
-  bool visitTextSpan(bool visitor(TextSpan span));
-
   /// Walks this [InlineSpan] and any descendants in pre-order and calls `visitor`
   /// for each span that has content.
   ///

packages/flutter/lib/src/painting/placeholder_span.dart

@@ -60,15 +60,6 @@ abstract class PlaceholderSpan extends InlineSpan {
     }
   }
 
-  // TODO(garyq): Remove this after next stable release.
-  /// The [visitTextSpan] method is invalid on [PlaceholderSpan]s
-  @override
-  @Deprecated('Use to visitChildren instead')
-  bool visitTextSpan(bool visitor(TextSpan span)) {
-    assert(false, 'visitTextSpan is deprecated. Use visitChildren to support InlineSpans');
-    return false;
-  }
-
   /// Populates the `semanticsOffsets` and `semanticsElements` with the appropriate data
   /// to be able to construct a [SemanticsNode].
   ///

packages/flutter/lib/src/painting/text_painter.dart

@@ -164,13 +164,8 @@ class TextPainter {
   /// The (potentially styled) text to paint.
   ///
   /// After this is set, you must call [layout] before the next call to [paint].
-  /// This and [textDirection] must be non-null before you call [layout].
   ///
-  /// The [InlineSpan] this provides is in the form of a tree that may contain
-  /// multiple instances of [TextSpan]s and [WidgetSpan]s. To obtain a plaintext
-  /// representation of the contents of this [TextPainter], use [InlineSpan.toPlainText]
-  /// to get the full contents of all nodes in the tree. [TextSpan.text] will
-  /// only provide the contents of the first node in the tree.
+  /// This and [textDirection] must be non-null before you call [layout].
   InlineSpan get text => _text;
   InlineSpan _text;
   set text(InlineSpan value) {

packages/flutter/lib/src/painting/text_span.dart

@@ -205,11 +205,8 @@ class TextSpan extends InlineSpan {
       builder.pop();
   }
 
-  /// Walks this [TextSpan] and its descendants in pre-order and calls [visitor]
+  /// Walks this text span and its descendants in pre-order and calls [visitor]
   /// for each span that has text.
-  ///
-  /// When `visitor` returns true, the walk will continue. When `visitor` returns
-  /// false, then the walk will end.
   @override
   bool visitChildren(InlineSpanVisitor visitor) {
     if (text != null) {
@@ -225,30 +222,6 @@ class TextSpan extends InlineSpan {
     return true;
   }
 
-  // TODO(garyq): Remove this after next stable release.
-  /// Walks this [TextSpan] and any descendants in pre-order and calls `visitor`
-  /// for each span that has content.
-  ///
-  /// When `visitor` returns true, the walk will continue. When `visitor` returns
-  /// false, then the walk will end.
-  @override
-  @Deprecated('Use to visitChildren instead')
-  bool visitTextSpan(bool visitor(TextSpan span)) {
-    if (text != null) {
-      if (!visitor(this))
-        return false;
-    }
-    if (children != null) {
-      for (InlineSpan child in children) {
-        assert(child is TextSpan, 'visitTextSpan is deprecated. Use visitChildren to support InlineSpans');
-        final TextSpan textSpanChild = child;
-        if (!textSpanChild.visitTextSpan(visitor))
-          return false;
-      }
-    }
-    return true;
-  }
-
   /// Returns the text span that contains the given position in the text.
   @override
   InlineSpan getSpanForPositionVisitor(TextPosition position, Accumulator offset) {