Avoid some explicit WebSpeechRecognitionHandle() conversions.

public/web/WebSpeechRecognitionHandle.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 41 matching lines @@
 
     BLINK_EXPORT void reset();
     BLINK_EXPORT void assign(const WebSpeechRecognitionHandle&);
 
     // Comparison functions are provided so that WebSpeechRecognitionHandle objects
     // can be stored in a hash map.
     BLINK_EXPORT bool equals(const WebSpeechRecognitionHandle&) const;
     BLINK_EXPORT bool lessThan(const WebSpeechRecognitionHandle&) const;
 
 #if BLINK_IMPLEMENTATION
-    explicit WebSpeechRecognitionHandle(SpeechRecognition*);
-    WebSpeechRecognitionHandle& operator=(SpeechRecognition*);
+    WebSpeechRecognitionHandle(SpeechRecognition*);
     operator SpeechRecognition*() const;
 #endif
 
 private:
     WebPrivatePtr<SpeechRecognition> m_private;
 };
 
 inline bool operator==(const WebSpeechRecognitionHandle& a, const WebSpeechRecognitionHandle& b)
 {
     return a.equals(b);
 }
 
 inline bool operator!=(const WebSpeechRecognitionHandle& a, const WebSpeechRecognitionHandle& b)
 {
     return !(a == b);
 }
 
 inline bool operator<(const WebSpeechRecognitionHandle& a, const WebSpeechRecognitionHandle& b)
 {
     return a.lessThan(b);
 }
 
 } // namespace blink
 
 #endif // WebSpeechRecognitionHandle_h