Migration guide for deprecations removed after 3.16 release (#10024)

This adds the migration guide for the deprecations that have been
removed since the 3.16 release.

Fixes flutter/flutter#139243

---------

Co-authored-by: Parker Lougheed <parlough@gmail.com>

src/release/breaking-changes/3-16-deprecations.md

@@ -0,0 +1,276 @@
+---
+title: Deprecated API removed after v3.16
+description: >-
+  After reaching end of life, the following deprecated APIs
+  were removed from Flutter.
+---
+
+## Summary
+
+In accordance with Flutter's [Deprecation Policy][],
+deprecated APIs that reached end of life after the
+3.16 stable release have been removed.
+
+All affected APIs have been compiled into this
+primary source to aid in migration.
+To further aid your migration, check out this
+[quick reference sheet][].
+
+[Deprecation Policy]: {{site.repo.flutter}}/wiki/Tree-hygiene#deprecation
+[quick reference sheet]: {{site.url}}/go/deprecations-removed-after-3-16
+
+## Changes
+
+This section lists the deprecations by the package and affected class.
+
+### Button `styleFrom` properties
+
+Package: flutter
+Supported by Flutter Fix: yes
+
+The `TextButton`, `ElevatedButton` and `OutlinedButton` widgets all have a
+static `styleFrom` method for generating the `ButtonStyle`. The following color
+properties of this method for each class were deprecated in v3.1:
+
+* `TextButton.styleFrom`
+  * `primary`
+  * `onSurface`
+* `ElevatedButton.styleFrom`
+  * `primary`
+  * `onPrimary`
+  * `onSurface`
+* `OutlinedButton.styleFrom`
+  * `primary`
+  * `onSurface`
+
+These changes better aligned the API with updated Material Design
+specifications. The changes also provided more clarity in how the colors would
+be applied to the buttons, by replacing these properties with `backgroundColor`,
+`foregroundColor`, and `disabledForegroundColor`.
+
+**Migration guide**
+
+Code before migration:
+
+```dart
+TextButton.styleFrom(
+  primary: Colors.red,
+  onSurface: Colors.black,
+);
+ElevatedButton.styleFrom(
+  primary: Colors.red,
+  onPrimary: Colors.blue,
+  onSurface: Colors.black,
+);
+OutlinedButton.styleFrom(
+  primary: Colors.red,
+  onSurface: Colors.black,
+);
+```
+
+Code after migration:
+
+```dart
+TextButton.styleFrom(
+  foregroundColor: Colors.red,
+  disabledForegroundColor: Colors.black,
+);
+ElevatedButton.styleFrom(
+  backgroundColor: Colors.red,
+  foregroundColor: Colors.blue,
+  disabledForegroundColor: Colors.black,
+);
+OutlinedButton.styleFrom(
+  foregroundColor: Colors.red,
+  disabledForegroundColor: Colors.black,
+);
+```
+
+**References**
+
+API documentation:
+
+* [`TextButton`][]
+* [`ElevatedButton`][]
+* [`OutlinedButton`][]
+* [`ButtonStyle`][]
+
+Relevant PRs:
+
+* Deprecated in [#105291][]
+* Removed in [#139267][]
+
+[`TextButton`]: {{site.api}}/flutter/material/TextButton-class.html
+[`ElevatedButton`]: {{site.api}}/flutter/material/ElevatedButton-class.html
+[`OutlinedButton`]: {{site.api}}/flutter/material/OutlinedButton-class.html
+[`ButtonStyle`]: {{site.api}}/flutter/material/ButtonStyle-class.html
+
+[#105291]: {{site.repo.flutter}}/pull/105291
+[#139267]: {{site.repo.flutter}}/pull/139267
+
+---
+
+### ThemeData.selectedRowColor
+
+Package: flutter
+Supported by Flutter Fix: yes
+
+The `selectedRowColor` property of `ThemeData` was deprecated in v3.1.
+
+The property was no longer used by the framework, as widgets using it migrated
+to other component themes or no longer required it in the updated specification
+for Material Design.
+
+**Migration guide**
+
+Code before migration:
+
+```dart
+ThemeData(
+  // ...
+  selectedRowColor: Colors.pink, // Would have no effect.  
+);
+```
+
+Code after migration:
+
+```dart
+ThemeData(
+  // ...
+  // Remove uses.  
+);
+```
+
+**References**
+
+API documentation:
+
+* [`ThemeData`][]
+
+Relevant PRs:
+
+* Deprecated in [#109070][]
+* Removed in [#139080][]
+
+[`ThemeData`]: {{site.api}}/flutter/material/ThemeData-class.html
+
+[#109070]: {{site.repo.flutter}}/pull/109070
+[#139080]: {{site.repo.flutter}}/pull/139080
+
+---
+
+### NavigatorState.focusScopeNode
+
+Package: flutter
+Supported by Flutter Fix: yes
+
+The `focusScopeNode` property of `NavigatorState` was deprecated in v3.1.
+
+This change was made to resolve several issues stemming around the
+`FocusScopeNode` introduced by the `Navigator`. Instead, the `FocusScope`
+was moved to enclose the topmost `Navigator` in a `WidgetsApp`.
+`NavigatorState` was changed to contain its own `FocusNode`, from where it can
+refer to its `FocusNode.enclosingScope` to access the correct `FocusScopeNode`.
+
+**Migration guide**
+
+Code before migration:
+
+```dart
+Navigator.of(context).focusScopeNode;
+
+```
+
+Code after migration:
+
+```dart
+Navigator.of(context).focusNode.enclosingScope!;
+```
+
+**References**
+
+API documentation:
+
+* [`Navigator`][]
+* [`NavigatorState`][]
+* [`FocusScope`][]
+* [`FocusScopeNode`][]
+* [`FocusNode`][]
+
+Relevant PRs:
+
+* Deprecated in [#109702][]
+* Removed in [#139260][]
+
+[`Navigator`]: {{site.api}}/flutter/widgets/Navigator-class.html
+[`NavigatorState`]: {{site.api}}/flutter/widgets/NavigatorState-class.html
+[`FocusScope`]: {{site.api}}/flutter/widgets/FocusScope-class.html
+[`FocusScopeNode`]: {{site.api}}/flutter/widgets/FocusScopeNode-class.html
+[`FocusNode`]: {{site.api}}/flutter/widgets/FocusNode-class.html
+
+[#109702]: {{site.repo.flutter}}/pull/109702
+[#139260]: {{site.repo.flutter}}/pull/139260
+
+---
+
+### PlatformMenuBar.body
+
+Package: flutter
+Supported by Flutter Fix: yes
+
+The `body` property of `PlatformMenuBar` was deprecated in v3.1.
+
+This change was made to align `PlatformMenuBar` with other widgets in the
+framework, renaming it to `child`.
+
+**Migration guide**
+
+Code before migration:
+
+```dart
+PlatformMenuBar(
+  body: myWidget,
+);
+```
+
+Code after migration:
+
+```dart
+PlatformMenuBar(
+  child: myWidget,
+);
+```
+
+**References**
+
+API documentation:
+
+* [`PlatformMenuBar`][]
+
+Relevant PRs:
+
+* Deprecated in [#104565][]
+* Removed in [#138509][]
+
+[`PlatformMenuBar`]: {{site.api}}/flutter/widgets/PlatformMenuBar-class.html
+
+[#104565]: {{site.repo.flutter}}/pull/104565
+[#138509]: {{site.repo.flutter}}/pull/138509
+
+---
+
+The [previously announced][] deprecations for `TextTheme`, `WidgetInspectorService`,
+and `WidgetInspectorServiceExtensions` were not removed during this cycle.
+The `WidgetInspectorService` and `WidgetInspectorServiceExtensions`
+deprecation on `setPubRootDirectories` has been extended another year to allow
+IDEs and other customer to migrate.
+Expect the `TextTheme` deprecations to be removed in the next cycle, which will
+be announced again when it comes.
+
+[previously announced]: https://groups.google.com/g/flutter-announce/c/DLnuqZo714o
+
+---
+
+## Timeline
+
+In stable release: TBD

src/release/breaking-changes/index.md

@@ -37,13 +37,15 @@ release, and listed in alphabetical order:
 * [Default multitouch scrolling][]
 * [Deprecate imperative apply of Flutter's Gradle plugins][]
 * [Rename MemoryAllocations to FlutterMemoryAllocations][]
+* [Deprecated API removed after v3.16][]
 
 [Migrate RawKeyEvent/RawKeyboard system to KeyEvent/HardwareKeyboard system]: {{site.url}}/release/breaking-changes/key-event-migration
 [Deprecate `TextField.canRequestFocus`]: {{site.url}}/release/breaking-changes/can-request-focus
 [Accessibility traversal order of tooltip changed]: {{site.url}}/release/breaking-changes/tooltip-semantics-order
 [Default multitouch scrolling]: {{site.url}}/release/breaking-changes/multi-touch-scrolling
 [Deprecate imperative apply of Flutter's Gradle plugins]: {{site.url}}/release/breaking-changes/flutter-gradle-plugin-apply
 [Rename MemoryAllocations to FlutterMemoryAllocations]: {{site.url}}/release/breaking-changes/flutter-memory-allocations
+[Deprecated API removed after v3.16]: {{site.url}}/release/breaking-changes/3-16-deprecations
 
 ### Released in Flutter 3.16