[child_view] Move mediaplayer Childview use to SDK

TEST: set_root_view mediaplayer_flutter
SCN-898 #comment
SCN-1033 #comment
SCN-1214 #comment

Change-Id: Id9c2952b20cdaacce9b509fb8237d58347798a78
diff --git a/examples/mediaplayer/mediaplayer_flutter/BUILD.gn b/examples/mediaplayer/mediaplayer_flutter/BUILD.gn
index 3cb3b65..c61c280 100644
--- a/examples/mediaplayer/mediaplayer_flutter/BUILD.gn
+++ b/examples/mediaplayer/mediaplayer_flutter/BUILD.gn
@@ -23,7 +23,6 @@
         "//topaz/public/dart/fuchsia",
         "//topaz/public/lib/app/dart",
         "//topaz/public/lib/mediaplayer/flutter",
-        "//topaz/public/lib/ui/flutter",
       ]
     },
   ]
diff --git a/public/lib/mediaplayer/flutter/BUILD.gn b/public/lib/mediaplayer/flutter/BUILD.gn
index 724d7d3..eda016c 100644
--- a/public/lib/mediaplayer/flutter/BUILD.gn
+++ b/public/lib/mediaplayer/flutter/BUILD.gn
@@ -22,6 +22,5 @@
     "//topaz/public/dart/fuchsia_scenic_flutter",
     "//topaz/public/lib/app/dart",
     "//topaz/public/lib/mediaplayer/dart",
-    "//topaz/public/lib/ui/flutter",
   ]
 }
diff --git a/public/lib/mediaplayer/flutter/media_player.dart b/public/lib/mediaplayer/flutter/media_player.dart
index 7070908..ee4b6b7 100644
--- a/public/lib/mediaplayer/flutter/media_player.dart
+++ b/public/lib/mediaplayer/flutter/media_player.dart
@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:fuchsia_scenic_flutter/child_view.dart' show ChildView;
 import 'package:lib.mediaplayer.flutter/media_player_controller.dart';
 import 'package:lib.mediaplayer.flutter/progress_notifier.dart';
-import 'package:lib.ui.flutter/child_view.dart';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
diff --git a/public/lib/mediaplayer/flutter/media_player_controller.dart b/public/lib/mediaplayer/flutter/media_player_controller.dart
index 671eb8a..e8f37f9 100644
--- a/public/lib/mediaplayer/flutter/media_player_controller.dart
+++ b/public/lib/mediaplayer/flutter/media_player_controller.dart
@@ -13,8 +13,6 @@
 import 'package:fuchsia_scenic_flutter/child_view_connection.dart'
     show ChildViewConnection;
 import 'package:lib.mediaplayer.dart/audio_player_controller.dart';
-import 'package:lib.ui.flutter/child_view.dart' as deprecated
-    show ChildViewConnection;
 import 'package:zircon/zircon.dart';
 
 /// Controller for MediaPlayer widgets.
@@ -24,8 +22,6 @@
 
   Timer _hideTimer;
 
-  bool _shouldCreateNewChildView = false;
-  deprecated.ChildViewConnection _deprecatedVideoViewConnection;
   ChildViewConnection _videoViewConnection;
 
   Size _videoSize = Size.zero;
@@ -39,9 +35,7 @@
     _close(); // Initialize stuff.
   }
 
-  set shouldCreateNewChildView(bool should) {
-    _shouldCreateNewChildView = should;
-  }
+  set shouldCreateNewChildView(bool should) {}
 
   @override
   void open(Uri uri, {HttpHeaders headers}) {
@@ -57,14 +51,8 @@
       assert(viewTokens.status == ZX.OK);
       player.createView2(viewTokens.first);
 
-      if (_shouldCreateNewChildView) {
-        _videoViewConnection =
-            ChildViewConnection.fromViewHolderToken(viewTokens.second);
-      } else {
-        _deprecatedVideoViewConnection =
-            deprecated.ChildViewConnection.fromViewHolderToken(
-                viewTokens.second);
-      }
+      _videoViewConnection =
+          ChildViewConnection.fromViewHolderToken(viewTokens.second);
     }
   }
 
@@ -76,7 +64,6 @@
   }
 
   void _close() {
-    _deprecatedVideoViewConnection = null;
     _videoViewConnection = null;
   }
 
@@ -146,8 +133,7 @@
   Size get videoPhysicalSize => hasVideo ? _videoSize : Size.zero;
 
   /// Gets the video view connection.
-  deprecated.ChildViewConnection get videoViewConnection =>
-      _deprecatedVideoViewConnection;
+  ChildViewConnection get videoViewConnection => _videoViewConnection;
   ChildViewConnection get videoViewConnectionNew => _videoViewConnection;
 
   @override