Merge the Sky Engine changes from the SkyDart branch

sky/engine/core/app/Application.h

Index: sky/engine/core/app/Application.h
diff --git a/sky/engine/core/app/Application.h b/sky/engine/core/app/Application.h
index f7a4d6eae0608136725479c3e8f1d60bf7d7c52b..fc1a7af7019e6ca75dbb77500830ea2b250874bb 100644
--- a/sky/engine/core/app/Application.h
+++ b/sky/engine/core/app/Application.h
@@ -10,7 +10,6 @@
 namespace blink {
 
 class Application : public AbstractModule {
-  DEFINE_WRAPPERTYPEINFO();
 public:
   static PassRefPtr<Application> create(ExecutionContext* context,
                                         PassRefPtr<Document> document,
@@ -23,6 +22,8 @@ public:
   void setTitle(const String& title) { title_ = title; }
   const String& title() { return title_; }
 
+  bool isApplication() const override { return true; }
+
 private:
   Application(ExecutionContext* context,
               PassRefPtr<Document> document,