AbstractModule should accept a PassRefPtr

sky/engine/core/app/Application.h

 // Copyright 2014 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.
 
 #ifndef SKY_ENGINE_CORE_APP_APPLICATION_H_
 #define SKY_ENGINE_CORE_APP_APPLICATION_H_
 
 #include "core/app/AbstractModule.h"
 
 namespace blink {
 
 class Application : public AbstractModule {
   DEFINE_WRAPPERTYPEINFO();
 public:
   static PassRefPtr<Application> create(ExecutionContext* context,
-                                        Document* document,
+                                        PassRefPtr<Document> document,
                                         const String& url) {
     return adoptRef(new Application(context, document, url));
   }
 
   virtual ~Application();
 
   void setTitle(const String& title) { title_ = title; }
   const String& title() { return title_; }
 
 private:
-  Application(ExecutionContext* context, Document* document, const String& url);
+  Application(ExecutionContext* context,
+              PassRefPtr<Document> document,
+              const String& url);
   const AtomicString& interfaceName() const override;
 
   String title_;
 };
 
 } // namespace blink
 
 #endif // SKY_ENGINE_CORE_APP_APPLICATION_H_