fixup! Update grammar in basic.dart #56251 (#56407)

packages/flutter/lib/src/widgets/basic.dart

@@ -3782,7 +3782,7 @@ class PositionedDirectional extends StatelessWidget {
 ///  * [Column], for a version of this widget that is always vertical.
 ///  * [Expanded], to indicate children that should take all the remaining room.
 ///  * [Flexible], to indicate children that should share the remaining room.
-///  * [Spacer], a widget that takes up space proportional to it's flex value.
+///  * [Spacer], a widget that takes up space proportional to its flex value.
 ///    that may be sized smaller (leaving some remaining room unused).
 ///  * The [catalog of layout widgets](https://flutter.dev/widgets/layout/).
 class Flex extends MultiChildRenderObjectWidget {
@@ -4122,7 +4122,7 @@ class Flex extends MultiChildRenderObjectWidget {
 ///  * [Expanded], to indicate children that should take all the remaining room.
 ///  * [Flexible], to indicate children that should share the remaining room but
 ///    that may by sized smaller (leaving some remaining room unused).
-///  * [Spacer], a widget that takes up space proportional to it's flex value.
+///  * [Spacer], a widget that takes up space proportional to its flex value.
 ///  * The [catalog of layout widgets](https://flutter.dev/widgets/layout/).
 class Row extends Flex {
   /// Creates a horizontal array of children.
@@ -4324,7 +4324,7 @@ class Row extends Flex {
 ///    that may size smaller (leaving some remaining room unused).
 ///  * [SingleChildScrollView], whose documentation discusses some ways to
 ///    use a [Column] inside a scrolling container.
-///  * [Spacer], a widget that takes up space proportional to it's flex value.
+///  * [Spacer], a widget that takes up space proportional to its flex value.
 ///  * The [catalog of layout widgets](https://flutter.dev/widgets/layout/).
 class Column extends Flex {
   /// Creates a vertical array of children.
@@ -4457,7 +4457,7 @@ class Flexible extends ParentDataWidget<FlexParentData> {
 ///
 /// {@tool dartpad --template=stateless_widget_material}
 /// This example shows how to use an [Expanded] widget in a [Column] so that
-/// it's middle child, a [Container] here, expands to fill the space.
+/// its middle child, a [Container] here, expands to fill the space.
 ///
 /// ![This results in two thin blue boxes with a larger amber box in between.](https://flutter.github.io/assets-for-api-docs/assets/widgets/expanded_column.png)
 ///
@@ -4539,7 +4539,7 @@ class Flexible extends ParentDataWidget<FlexParentData> {
 /// See also:
 ///
 ///  * [Flexible], which does not force the child to fill the available space.
-///  * [Spacer], a widget that takes up space proportional to it's flex value.
+///  * [Spacer], a widget that takes up space proportional to its flex value.
 ///  * The [catalog of layout widgets](https://flutter.dev/widgets/layout/).
 class Expanded extends Flexible {
   /// Creates a widget that expands a child of a [Row], [Column], or [Flex]