Rationalize Dart mojo and sky package structure

sky/framework/embedder.dart

-// Copyright 2015 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:mojo/public/dart/application.dart";
-import "dart:sky.internals" as internals;
-import "package:mojo/public/dart/bindings.dart" as bindings;
-import "package:mojo/public/dart/core.dart" as core;
-import "package:mojom/mojo/service_provider.mojom.dart";
-import "package:mojom/mojo/shell.mojom.dart";
-import "package:mojom/mojo/service_registry.mojom.dart";
-
-final _EmbedderImpl embedder = new _EmbedderImpl();
-
-class _EmbedderImpl {
-  ApplicationConnection _connection;
-  ServiceRegistryProxy _serviceRegistry;
-  ShellProxy _shell;
-  bool _internalsHasNoShell = false;
-
-  ShellProxy get shell {
-    if (_internalsHasNoShell || _shell != null) return _shell;
-
-    try {
-      _shell = new ShellProxy.fromHandle(
-          new core.MojoHandle(internals.takeShellProxyHandle()));
-    } catch (e) {
-      _internalsHasNoShell = true;
-    }
-    return _shell;
-  }
-
-  ApplicationConnection get connection {
-    if (_connection == null) {
-      var stubHandle =
-          new core.MojoHandle(internals.takeServicesProvidedToEmbedder());
-      var proxyHandle =
-          new core.MojoHandle(internals.takeServicesProvidedByEmbedder());
-      _connection = new ApplicationConnection(stubHandle.isValid
-          ? new ServiceProviderStub.fromHandle(stubHandle)
-          : null, proxyHandle.isValid
-          ? new ServiceProviderProxy.fromHandle(proxyHandle)
-          : null);
-    }
-    return _connection;
-  }
-
-  ApplicationConnection connectToApplication(String url) {
-    var proxy = new ServiceProviderProxy.unbound();
-    var stub = new ServiceProviderStub.unbound();
-    shell.ptr.connectToApplication(url, proxy, stub);
-    return new ApplicationConnection(stub, proxy);
-  }
-
-  void connectToService(String url, bindings.ProxyBase proxy) {
-    var appSp = new ServiceProviderProxy.unbound();
-    shell.ptr.connectToApplication(url, appSp, null);
-    var pipe = new core.MojoMessagePipe();
-    proxy.impl.bind(pipe.endpoints[0]);
-    appSp.ptr.connectToService(proxy.name, pipe.endpoints[1]);
-    appSp.close();
-  }
-
-  ServiceRegistryProxy get serviceRegistry {
-    if (_serviceRegistry == null) {
-      _serviceRegistry = new ServiceRegistryProxy.fromHandle(
-          new core.MojoHandle(internals.takeServiceRegistry()));
-    }
-    return _serviceRegistry;
-  }
-}