Simple doc fix (#23753)

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

@@ -1529,18 +1529,18 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   /// required to obey the given constraints.
   ///
   /// If the parent reads information computed during the child's layout, the
-  /// parent must pass true for parentUsesSize. In that case, the parent will be
-  /// marked as needing layout whenever the child is marked as needing layout
+  /// parent must pass true for `parentUsesSize`. In that case, the parent will
+  /// be marked as needing layout whenever the child is marked as needing layout
   /// because the parent's layout information depends on the child's layout
   /// information. If the parent uses the default value (false) for
-  /// parentUsesSize, the child can change its layout information (subject to
+  /// `parentUsesSize`, the child can change its layout information (subject to
   /// the given constraints) without informing the parent.
   ///
   /// Subclasses should not override [layout] directly. Instead, they should
   /// override [performResize] and/or [performLayout]. The [layout] method
   /// delegates the actual work to [performResize] and [performLayout].
   ///
-  /// The parent's performLayout method should call the [layout] of all its
+  /// The parent's [performLayout] method should call the [layout] of all its
   /// children unconditionally. It is the [layout] method's responsibility (as
   /// implemented here) to return early if the child does not need to do any
   /// work to update its layout information.