Expose some sky_viewer plumbing to allow for reuse

sky/viewer/sky_viewer_base.cc

+// 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.
+
+#include "sky/viewer/sky_viewer_base.h"
+
+#include "sky/engine/public/web/Sky.h"
+#include "sky/viewer/runtime_flags.h"
+
+namespace sky {
+
+SkyViewerBase::SkyViewerBase() {
+}
+
+SkyViewerBase::~SkyViewerBase() {
+  blink::shutdown();
+}
+
+void SkyViewerBase::Initialize(mojo::ApplicationImpl* app) {
+  RuntimeFlags::Initialize(app);
+
+  mojo::NetworkServicePtr network_service;
+  app->ConnectToService("mojo:network_service", &network_service);
+  platform_impl_.reset(new PlatformImpl(network_service.Pass()));
+  blink::initialize(platform_impl_.get());
+
+  mojo::icu::Initialize(app);
+  tracing_.Initialize(app);
+}
+
+bool SkyViewerBase::ConfigureIncomingConnection(
+    mojo::ApplicationConnection* connection) {
+  connection->AddService<mojo::ContentHandler>(this);
+  return true;
+}
+
+}  // namespace sky