Split initialization test case into its own file

Author: cbenhagen

packages/video_player/video_player/test/video_player_initialization_test.dart

@@ -0,0 +1,22 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:video_player/video_player.dart';
+
+import 'video_player_test.dart' show FakeVideoPlayerPlatform;
+
+void main() {
+  test('plugin initialized', () async {
+    WidgetsFlutterBinding.ensureInitialized();
+    FakeVideoPlayerPlatform fakeVideoPlayerPlatform = FakeVideoPlayerPlatform();
+
+    final VideoPlayerController controller = VideoPlayerController.network(
+      'https://127.0.0.1',
+    );
+    await controller.initialize();
+    expect(fakeVideoPlayerPlatform.calls.first.method, 'init');
+  });
+}

packages/video_player/video_player/test/video_player_test.dart

@@ -91,14 +91,6 @@ void main() {
       fakeVideoPlayerPlatform = FakeVideoPlayerPlatform();
     });
 
-    test('plugin initialized', () async {
-      final VideoPlayerController controller = VideoPlayerController.network(
-        'https://127.0.0.1',
-      );
-      await controller.initialize();
-      expect(fakeVideoPlayerPlatform.calls.first.method, 'init');
-    });
-
     group('initialize', () {
       test('asset', () async {
         final VideoPlayerController controller = VideoPlayerController.asset(