Make WebPrivatePtr capable of wrapping garbage collected objects.

public/web/WebSpeechRecognitionResult.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 30 matching lines @@
 public:
     WebSpeechRecognitionResult() { }
     WebSpeechRecognitionResult(const WebSpeechRecognitionResult& result) { assign(result); }
     ~WebSpeechRecognitionResult() { reset(); }
 
     BLINK_EXPORT void assign(const WebVector<WebString>& transcripts, const WebVector<float>& confidences, bool final);
     BLINK_EXPORT void assign(const WebSpeechRecognitionResult&);
     BLINK_EXPORT void reset();
 
 #if BLINK_IMPLEMENTATION
-    operator WTF::PassRefPtr<WebCore::SpeechRecognitionResult>() const;
+    operator PassRefPtrWillBeRawPtr<WebCore::SpeechRecognitionResult>() const;
 #endif
 
 private:
     WebPrivatePtr<WebCore::SpeechRecognitionResult> m_private;
 };
 
 } // namespace blink
 
 #endif // WebSpeechRecognitionResult_h