Add a sky_engine package to contain the dart:sky SDK extensions

packages/flutter/BUILD.gn

@@ -108,21 +108,11 @@ dart_pkg("sky") {
     "//mojo/dart/mojom",
     "//mojo/public/dart:mojo",
     "//sky/engine/bindings",
-    "//sky/services/testing:interfaces",
+    "//sky/packages/sky_engine",
     "//sky/services/media:interfaces",
+    "//sky/services/testing:interfaces",
     "//third_party/dart-pkg",
   ]
-
-  sdk_ext_directory = "$root_gen_dir/sky/bindings"
-  sdk_ext_files = [
-    "//sky/engine/bindings/sky_internals.dart",
-    "//sky/engine/bindings/builtin_natives.dart",
-  ]
-  sdk_ext_mappings = [
-    "dart:sky,dart_sky.dart",
-    "dart:sky.internals,sky_internals.dart",
-    "dart:sky_builtin_natives,builtin_natives.dart",
-  ]
 }
 
 action("material_design_icons") {

packages/flutter/pubspec.yaml

+name: sky
+version: 0.0.21
 author: Chromium Authors <sky-dev@googlegroups.com>
+description: A framework for writing Sky applications
+homepage: https://github.com/domokit/sky_engine/tree/master/sky/sdk
 dependencies:
   cassowary: ^0.1.7
   mojo_services: ^0.0.15
   mojo: ^0.0.17
   mojom: ^0.0.17
   newton: ^0.1.0
+  sky_engine: ^0.0.1
   sky_tools: ^0.0.2
   vector_math: ^1.4.3
-description: Dart files to support executing inside Sky
 environment:
   sdk: '>=1.8.0 <2.0.0'
-homepage: https://github.com/domokit/mojo/tree/master/sky
-name: sky
-version: 0.0.21