Add support for native bindings generation to dartgenerator.py.

client/dom/src/native_DOMImplementation.dart

+class Utils {
+  static List convertToList(List list) {
+    // FIXME: [possible optimization]: do not copy the array if Dart_IsArray is fine w/ it.
+    final length = list.length;
+    List result = new List(length);
+    result.copyFrom(list, 0, 0, length);
+    return result;
+  }
+
+  static makeNotImplementedException() {
+    return const NotImplementedException();
+  }
+
+  static window() native "TopLevel_Window";
+
+  static SendPort spawnDomIsolate(Window window, String entryPoint) native "Utils_spawnDomIsolate";
+}
+
+/*
+ * [NPObjectBase] is native wrapper class injected from embedder's code.
+ */
+class NPObject extends DOMWrapperBase {
+  static NPObject retrieve(String key) native "NPObject_retrieve";
+  property(String propertyName) native "NPObject_property";
+  invoke(String methodName, [ObjectArray args = null]) native "NPObject_invoke";
+
+  static _createNPObject() => new NPObject._createNPObject();
+  NPObject._createNPObject();
+}
+
+class DOMWindowCrossFrameImplementation extends DOMWrapperBase implements DOMWindow {
+  // Fields.
+  History get history() native "DOMWindow_history_cross_frame_Getter";
+  Location get location() native "DOMWindow_location_cross_frame_Getter";
+  bool get closed() native "DOMWindow_closed_Getter";
+  int get length() native "DOMWindow_length_Getter";
+  DOMWindow get opener() native "DOMWindow_opener_Getter";
+  DOMWindow get parent() native "DOMWindow_parent_Getter";
+  DOMWindow get top() native "DOMWindow_top_Getter";
+
+  // Methods.
+  void focus() native "DOMWindow_focus_Callback";
+  void blur() native "DOMWindow_blur_Callback";
+  void close() native "DOMWindow_close_Callback";
+  void postMessage([_arg0, _arg1, _arg2]) native "DOMWindow_postMessage_Callback";
+
+  // Implementation support.
+  static DOMWindowCrossFrameImplementation _createDOMWindowCrossFrameImplementation() => new DOMWindowCrossFrameImplementation._createDOMWindowCrossFrameImplementation();
+  DOMWindowCrossFrameImplementation._createDOMWindowCrossFrameImplementation();
+
+  String get typeName() => "DOMWindow";
+}
+
+class HistoryCrossFrameImplementation extends DOMWrapperBase implements History {
+  // Methods.
+  void back() native "History_back_Callback";
+  void forward() native "History_forward_Callback";
+  void go(int distance) native "History_go_Callback";
+
+  // Implementation support.
+  static HistoryCrossFrameImplementation _createHistoryCrossFrameImplementation() => new HistoryCrossFrameImplementation._createHistoryCrossFrameImplementation();
+  HistoryCrossFrameImplementation._createHistoryCrossFrameImplementation();
+
+  String get typeName() => "History";
+}
+
+class LocationCrossFrameImplementation extends DOMWrapperBase implements Location {
+  // Fields.
+  void set href(String) native "Location_href_Setter";
+
+  // Implementation support.
+  static LocationCrossFrameImplementation _createLocationCrossFrameImplementation() => new LocationCrossFrameImplementation._createLocationCrossFrameImplementation();
+  LocationCrossFrameImplementation._createLocationCrossFrameImplementation();
+
+  String get typeName() => "Location";
+}