Suppress generation of JsGlobal and JsType code and use window as the default value instead of {} f…

test/codegen/expect/dom.js

 var dom;
 (function(exports) {
   'use strict';
-  class JsType extends dart.Object {
-    JsType(opt$) {
+  class JsName extends dart.Object {
+    JsName(opt$) {
       let name = opt$.name === void 0 ? null : opt$.name;
       this.name = name;
     }
   }
-  class JsGlobal extends dart.Object {
-    JsGlobal() {
-    }
-  }
   class Overload extends dart.Object {
     Overload() {
     }
   }
   let overload = new Overload();
-  exports.document = null;
-  class Document extends dart.Object {
-  }
-  class Element extends dart.Object {
-    Element() {
-      this.textContent = null;
-    }
-  }
   class Event extends dart.Object {
   }
-  class InputElement extends Element {
-    InputElement() {
-      this.value = null;
-      super.Element();
-    }
-  }
-  class CanvasElement extends Element {
-  }
   class RenderingContext extends dart.Object {
   }
-  class CanvasRenderingContext2D extends dart.Object {
-    CanvasRenderingContext2D() {
-      this.globalAlpha = null;
-      this.globalCompositeOperation = null;
-      this.strokeStyle = null;
-      this.fillStyle = null;
-      this.shadowOffsetX = null;
-      this.shadowOffsetY = null;
-      this.shadowBlur = null;
-      this.shadowColor = null;
-    }
-  }
   class CanvasDrawingStyles extends dart.Object {
     CanvasDrawingStyles() {
       this.lineWidth = null;
       this.lineCap = null;
       this.lineJoin = null;
       this.miterLimit = null;
       this.lineDashOffset = null;
       this.font = null;
       this.textAlign = null;
       this.textBaseline = null;
     }
   }
   class CanvasPathMethods extends dart.Object {
   }
-  class CanvasGradient extends dart.Object {
-  }
-  class CanvasPattern extends dart.Object {
-  }
-  class TextMetrics extends dart.Object {
-  }
-  class ImageData extends dart.Object {
-  }
   // Exports:
-  exports.JsType = JsType;
-  exports.JsGlobal = JsGlobal;
+  exports.JsName = JsName;
   exports.Overload = Overload;
   exports.overload = overload;
-  exports.Document = Document;
-  exports.Element = Element;
   exports.Event = Event;
-  exports.InputElement = InputElement;
-  exports.CanvasElement = CanvasElement;
   exports.RenderingContext = RenderingContext;
-  exports.CanvasRenderingContext2D = CanvasRenderingContext2D;
   exports.CanvasDrawingStyles = CanvasDrawingStyles;
   exports.CanvasPathMethods = CanvasPathMethods;
-  exports.CanvasGradient = CanvasGradient;
-  exports.CanvasPattern = CanvasPattern;
-  exports.TextMetrics = TextMetrics;
-  exports.ImageData = ImageData;
-})(dom || (dom = {}));
+})(dom || (dom = window));