Expose some sky_viewer plumbing to allow for reuse

sky/viewer/sky_loader.cc

+// Copyright 2014 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.
+
+#include "sky/viewer/sky_loader.h"
+
+#include "base/bind.h"
+#include "sky/viewer/document_view.h"
+
+namespace sky {
+
+SkyLoader::SkyLoader(mojo::Shell* shell,
+                     mojo::URLResponsePtr initial_app_to_load)
+    : shell_(shell), initial_app_to_load_(initial_app_to_load.Pass()) {
+  mojo::ServiceProviderPtr service_provider;
+  shell_->ConnectToApplication("mojo:network_service",
+                               mojo::GetProxy(&service_provider), nullptr);
+  mojo::ConnectToService(service_provider.get(), &network_service_);
+}
+
+SkyLoader::~SkyLoader() {
+}
+
+void SkyLoader::LoadApplication(
+    mojo::InterfaceRequest<mojo::ServiceProvider> services,
+    mojo::ServiceProviderPtr exposed_services,
+    const mojo::String& url) {
+  if (initial_app_to_load_) {
+    OnApplicationLoaded(mojo::URLLoaderPtr(), services.Pass(),
+                        exposed_services.Pass(), initial_app_to_load_.Pass());
+    return;
+  }
+
+  mojo::URLLoaderPtr loader;
+  network_service_->CreateURLLoader(mojo::GetProxy(&loader));
+  mojo::URLRequestPtr request(mojo::URLRequest::New());
+  request->url = url;
+  request->auto_follow_redirects = true;
+
+  // |loader| will be pass to the OnResponseReceived method through a
+  // callback. Because order of evaluation is undefined, a reference to the
+  // raw pointer is needed.
+  mojo::URLLoader* raw_loader = loader.get();
+  raw_loader->Start(
+      request.Pass(),
+      base::Bind(&SkyLoader::OnApplicationLoaded, base::Unretained(this),
+                 base::Passed(&loader), base::Passed(&services),
+                 base::Passed(&exposed_services)));
+}
+
+void SkyLoader::OnApplicationLoaded(
+    mojo::URLLoaderPtr loader,
+    mojo::InterfaceRequest<mojo::ServiceProvider> services,
+    mojo::ServiceProviderPtr exposed_services,
+    mojo::URLResponsePtr response) {
+  new DocumentView(services.Pass(), exposed_services.Pass(), response.Pass(),
+                   shell_);
+}
+
+}  // namespace sky