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

remoting/host/mac/me2me_preference_pane.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.
 
 #import <Cocoa/Cocoa.h>
 #import <PreferencePanes/PreferencePanes.h>
 #import <SecurityInterface/SFAuthorizationView.h>
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "third_party/jsoncpp/source/include/json/value.h"
 
 namespace remoting {
 
 // This is an implementation of JsonHostConfig which does not use code from
 // the "base" target, so it can be built for 64-bit on Mac OS X.
 
 // TODO(lambroslambrou): Once the "base" target has 64-bit support, remove this
 // implementation and use the one in remoting/host/json_host_config.h - see
 // http://crbug.com/128122.
 class JsonHostConfig {
  public:
-  JsonHostConfig(const std::string& filename);
+  explicit JsonHostConfig(const std::string& filename);
   ~JsonHostConfig();
 
   bool Read();
   bool GetString(const std::string& path, std::string* out_value) const;
   std::string GetSerializedData() const;
 
  private:
   Json::Value config_;
   std::string filename_;
 
@@ skipping 102 matching lines @@
 - (void)checkInstalledVersion;
 
 - (void)mismatchAlertDidEnd:(NSAlert*)alert
                  returnCode:(NSInteger)returnCode
                 contextInfo:(void*)contextInfo;
 
 // Called when the user chooses OK when prompted to restart System Preferences.
 - (void)restartSystemPreferences;
 
 @end