Add DartController and friends

sky/engine/core/script/dom_dart_state.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/engine/config.h"
+#include "sky/engine/core/script/dom_dart_state.h"
+
+#include "sky/engine/core/dom/Document.h"
+#include "sky/engine/core/script/dart_loader.h"
+
+namespace blink {
+
+DOMDartState::DOMDartState(Document* document)
+    : document_(document), loader_(adoptPtr(new DartLoader(this))) {
+  DCHECK(document_);
+}
+
+DOMDartState::~DOMDartState() {
+}
+
+DOMDartState* DOMDartState::Current() {
+  return static_cast<DOMDartState*>(DartState::Current());
+}
+
+Document* DOMDartState::CurrentDocument() {
+  return Current()->document_.get();
+}
+
+LocalFrame* DOMDartState::CurrentFrame() {
+  return Current()->document_->frame();
+}
+
+LocalDOMWindow* DOMDartState::CurrentWindow() {
+  return Current()->document_->domWindow();
+}
+
+}