Remove explicit keyword from multi-argument constructors

chrome/browser/extensions/extension_pref_store.h

 // Copyright (c) 2011 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_PREF_STORE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_PREF_STORE_H_
 #pragma once
 
 #include <string>
 
 #include "base/time.h"
 #include "chrome/browser/extensions/extension_pref_value_map.h"
 #include "chrome/browser/prefs/value_map_pref_store.h"
 
 // A (non-persistent) PrefStore implementation that holds effective preferences
 // set by extensions. These preferences are managed by and fetched from an
 // ExtensionPrefValueMap.
 class ExtensionPrefStore : public ValueMapPrefStore,
                            public ExtensionPrefValueMap::Observer {
  public:
   // Constructs an ExtensionPrefStore for a regular or an incognito profile.
-  explicit ExtensionPrefStore(ExtensionPrefValueMap* extension_pref_value_map,
-                              bool incognito_pref_store);
+  ExtensionPrefStore(ExtensionPrefValueMap* extension_pref_value_map,
+                     bool incognito_pref_store);
   virtual ~ExtensionPrefStore();
 
  private:
   // Overrides for ExtensionPrefValueMap::Observer:
   virtual void OnInitializationCompleted();
   virtual void OnPrefValueChanged(const std::string& key);
   virtual void OnExtensionPrefValueMapDestruction();
 
   ExtensionPrefValueMap* extension_pref_value_map_;  // Weak pointer.
   bool incognito_pref_store_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionPrefStore);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PREF_STORE_H_