Merge null-safety plugins (#3324)

diff --git a/packages/plugin_platform_interface/CHANGELOG.md b/packages/plugin_platform_interface/CHANGELOG.md
index 01b5ff7..7df1834 100644
--- a/packages/plugin_platform_interface/CHANGELOG.md
+++ b/packages/plugin_platform_interface/CHANGELOG.md
@@ -1,3 +1,11 @@
+## 1.1.0-nullsafety.1
+
+* Bump Dart SDK to support null safety.
+
+## 1.1.0-nullsafety
+
+* Migrate to null safety.
+
 ## 1.0.3
 
 * Fix homepage in `pubspec.yaml`.
diff --git a/packages/plugin_platform_interface/analysis_options.yaml b/packages/plugin_platform_interface/analysis_options.yaml
new file mode 100644
index 0000000..f4819cd
--- /dev/null
+++ b/packages/plugin_platform_interface/analysis_options.yaml
@@ -0,0 +1,4 @@
+include: ../../analysis_options.yaml
+analyzer:
+  enable-experiment:
+    - non-nullable
diff --git a/packages/plugin_platform_interface/lib/plugin_platform_interface.dart b/packages/plugin_platform_interface/lib/plugin_platform_interface.dart
index be48719..cd87b04 100644
--- a/packages/plugin_platform_interface/lib/plugin_platform_interface.dart
+++ b/packages/plugin_platform_interface/lib/plugin_platform_interface.dart
@@ -41,7 +41,7 @@
 /// [MockPlatformInterfaceMixin] for a sample of using Mockito to mock a platform interface.
 abstract class PlatformInterface {
   /// Pass a private, class-specific `const Object()` as the `token`.
-  PlatformInterface({@required Object token}) : _instanceToken = token;
+  PlatformInterface({required Object token}) : _instanceToken = token;
 
   final Object _instanceToken;
 
diff --git a/packages/plugin_platform_interface/pubspec.yaml b/packages/plugin_platform_interface/pubspec.yaml
index ae11b14..05fc918 100644
--- a/packages/plugin_platform_interface/pubspec.yaml
+++ b/packages/plugin_platform_interface/pubspec.yaml
@@ -12,17 +12,17 @@
 # be done when absolutely necessary and after the ecosystem has already migrated to 1.X.Y version
 # that is forward compatible with 2.0.0 (ideally the ecosystem have migrated to depend on:
 # `plugin_platform_interface: >=1.X.Y <3.0.0`).
-version: 1.0.3
+version: 1.1.0-nullsafety.1
 
 repository: https://github.com/flutter/plugins/tree/master/packages/plugin_platform_interface
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
-  meta: ^1.0.0
+  meta: ^1.3.0-nullsafety.3
 
 dev_dependencies:
   mockito: ^4.1.1
-  test: ^1.9.4
-  pedantic: ^1.8.0
+  test: ^1.10.0-nullsafety.1
+  pedantic: ^1.10.0-nullsafety.1
diff --git a/packages/plugin_platform_interface/test/plugin_platform_interface_test.dart b/packages/plugin_platform_interface/test/plugin_platform_interface_test.dart
index 0488c20..b07dd4d 100644
--- a/packages/plugin_platform_interface/test/plugin_platform_interface_test.dart
+++ b/packages/plugin_platform_interface/test/plugin_platform_interface_test.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(egarciad): Remove once Mockito is migrated to null safety.
+// @dart = 2.9
 import 'package:mockito/mockito.dart';
 import 'package:test/test.dart';