Add missing (and remove superfluous) 'explicit' from constructors.

chrome/browser/extensions/extension_function_registry.h

 // Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_REGISTRY_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_REGISTRY_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 class ExtensionFunction;
 
 // A factory function for creating new ExtensionFunction instances.
 typedef ExtensionFunction* (*ExtensionFunctionFactory)();
 
 // Template for defining ExtensionFunctionFactory.
 template<class T>
 ExtensionFunction* NewExtensionFunction() {
   return new T();
 }
 
 // Contains a list of all known extension functions and allows clients to
 // create instances of them.
 class ExtensionFunctionRegistry {
  public:
   static ExtensionFunctionRegistry* GetInstance();
-  explicit ExtensionFunctionRegistry();
+  ExtensionFunctionRegistry();
   virtual ~ExtensionFunctionRegistry();
 
   // Resets all functions to their default values.
   void ResetFunctions();
 
   // Adds all function names to 'names'.
   void GetAllNames(std::vector<std::string>* names);
 
   // Allows overriding of specific functions (e.g. for testing).  Functions
   // must be previously registered.  Returns true if successful.
   bool OverrideFunction(const std::string& name,
                         ExtensionFunctionFactory factory);
 
   // Factory method for the ExtensionFunction registered as 'name'.
   ExtensionFunction* NewFunction(const std::string& name);
 
   template<class T>
   void RegisterFunction() {
     factories_[T::function_name()] = &NewExtensionFunction<T>;
   }
 
  private:
   typedef std::map<std::string, ExtensionFunctionFactory> FactoryMap;
   FactoryMap factories_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_REGISTRY_H_