Make collator ctor explicit.

third_party/WebKit/Source/wtf/text/Collator.h

 /*
  * Copyright (C) 2008 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 33 matching lines @@
   USING_FAST_MALLOC(Collator);
 
  public:
   enum Result { Equal = 0, Greater = 1, Less = -1 };
 
   // From ICU's uloc.h (ULOC_FULLNAME_CAPACITY)
   static const size_t ulocFullnameCapacity = 157;
 
   // Parsing is lenient; e.g. language identifiers (such as "en-US") are
   // accepted, too.
-  Collator(const char* locale);
+  explicit Collator(const char* locale);
 
   ~Collator();
   void setOrderLowerFirst(bool);
 
   static std::unique_ptr<Collator> userDefault();
 
   Result collate(const ::UChar*, size_t, const ::UChar*, size_t) const;
 
  private:
   void createCollator() const;
   void releaseCollator();
   void setEquivalentLocale(const char*, char*);
   mutable UCollator* m_collator;
 
   char* m_locale;
   char m_equivalentLocale[ulocFullnameCapacity];
   bool m_lowerFirst;
 };
 
 }  // namespace WTF
 
 using WTF::Collator;
 
 #endif