gn/linux: warnings as errors, turn on Wextra

chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.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_UI_ASH_LAUNCHER_CHROME_LAUNCHER_APP_MENU_ITEM_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_CHROME_LAUNCHER_APP_MENU_ITEM_H_
 
 #include "base/strings/string16.h"
 #include "ui/gfx/image/image.h"
 
 // A description for a menu item. It contains the menu item description as well
 // as the function which gets executed upon menu item click.
 class ChromeLauncherAppMenuItem {
  public:
   // To insert a separator before this item set |has_leading_separator|.
   ChromeLauncherAppMenuItem(const base::string16 title,
                             const gfx::Image* icon,
                             bool has_leading_separator);
 
   virtual ~ChromeLauncherAppMenuItem();
 
   // Retrieves the title for this menu option.
   const base::string16& title() const { return title_; }
 
   // Retrieves the icon for this menu option.
   const gfx::Image& icon() const { return icon_; }
 
   // Returns true if a separator should be inserted before this item.
-  const bool HasLeadingSeparator() const { return has_leading_separator_; }
+  bool HasLeadingSeparator() const { return has_leading_separator_; }
 
   // Returns true if the item is active.
   virtual bool IsActive() const;
 
   // Returns true if item is enabled.
   virtual bool IsEnabled() const;
 
   // Executes the option.
   // |event_flags| are the flags from the event which issued this command.
   // It can be used to check additional keyboard modifiers.
   virtual void Execute(int event_flags);
 
  private:
   const base::string16 title_;
   const gfx::Image icon_;
 
   // True if the item has a separator in front of it.
   const bool has_leading_separator_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeLauncherAppMenuItem);
 };
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_CHROME_LAUNCHER_APP_MENU_ITEM_H_