[shared_preferences] Endorse Windows (#3059)

Adds endorsement, and manual registration, of
shared_preferences_windows.

Fixes flutter/flutter#41719
diff --git a/packages/shared_preferences/shared_preferences/CHANGELOG.md b/packages/shared_preferences/shared_preferences/CHANGELOG.md
index 3f4edca..5a6a030 100644
--- a/packages/shared_preferences/shared_preferences/CHANGELOG.md
+++ b/packages/shared_preferences/shared_preferences/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.5.11
+
+* Support Windows by default.
+
 ## 0.5.10
 
 * Update package:e2e -> package:integration_test
diff --git a/packages/shared_preferences/shared_preferences/lib/shared_preferences.dart b/packages/shared_preferences/shared_preferences/lib/shared_preferences.dart
index b8d3452..c4c8710 100644
--- a/packages/shared_preferences/shared_preferences/lib/shared_preferences.dart
+++ b/packages/shared_preferences/shared_preferences/lib/shared_preferences.dart
@@ -11,6 +11,7 @@
 import 'package:shared_preferences_linux/shared_preferences_linux.dart';
 import 'package:shared_preferences_platform_interface/shared_preferences_platform_interface.dart';
 import 'package:shared_preferences_platform_interface/method_channel_shared_preferences.dart';
+import 'package:shared_preferences_windows/shared_preferences_windows.dart';
 
 /// Wraps NSUserDefaults (on iOS) and SharedPreferences (on Android), providing
 /// a persistent store for simple data.
@@ -31,10 +32,13 @@
       // Only do the initial registration if it hasn't already been overridden
       // with a non-default instance.
       if (!kIsWeb &&
-          Platform.isLinux &&
           SharedPreferencesStorePlatform.instance
               is MethodChannelSharedPreferencesStore) {
-        SharedPreferencesStorePlatform.instance = SharedPreferencesLinux();
+        if (Platform.isLinux) {
+          SharedPreferencesStorePlatform.instance = SharedPreferencesLinux();
+        } else if (Platform.isWindows) {
+          SharedPreferencesStorePlatform.instance = SharedPreferencesWindows();
+        }
       }
       _manualDartRegistrationNeeded = false;
     }
diff --git a/packages/shared_preferences/shared_preferences/pubspec.yaml b/packages/shared_preferences/shared_preferences/pubspec.yaml
index 04b7813..a27fce2 100644
--- a/packages/shared_preferences/shared_preferences/pubspec.yaml
+++ b/packages/shared_preferences/shared_preferences/pubspec.yaml
@@ -5,7 +5,7 @@
 # 0.5.y+z is compatible with 1.0.0, if you land a breaking change bump
 # the version to 2.0.0.
 # See more details: https://github.com/flutter/flutter/wiki/Package-migration-to-1.0.0
-version: 0.5.10
+version: 0.5.11
 
 flutter:
   plugin:
@@ -35,6 +35,7 @@
   shared_preferences_linux: ^0.0.2
   shared_preferences_macos: ^0.0.1
   shared_preferences_web: ^0.1.2
+  shared_preferences_windows: ^0.0.1
 
 dev_dependencies:
   flutter_test: