[cros] Add --stub-cros-settings option for testing.

chrome/browser/chromeos/cros_settings.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_CHROMEOS_CROS_SETTINGS_H_
 #define CHROME_BROWSER_CHROMEOS_CROS_SETTINGS_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 19 matching lines @@
  public:
   // Class factory.
   static CrosSettings* Get();
 
   // Helper function to test if given path is a value cros settings name.
   static bool IsCrosSettings(const std::string& path);
 
   // Sets |in_value| to given |path| in cros settings.
   void Set(const std::string& path, const base::Value& in_value);
 
-  // Fires system setting change notification.
-  // TODO(pastarmovj): Consider to remove this function from the public
-  // interface.
-  void FireObservers(const char* path);
-
   // Gets settings value of given |path| to |out_value|.
   const base::Value* GetPref(const std::string& path) const;
 
   // Starts a fetch from the trusted store for the value of |path| if not loaded
   // yet. It will call the |callback| function upon completion if a new fetch
   // was needed in which case the return value is false. Else it will return
   // true and won't call the |callback|.
   bool GetTrusted(const std::string& path,
                   const base::Closure& callback) const;
 
@@ skipping 35 matching lines @@
                               content::NotificationObserver* obs);
 
   // Returns the provider that handles settings with the path or prefix.
   CrosSettingsProvider* GetProvider(const std::string& path) const;
 
   // Forces all providers to reload their caches from the respective backing
   // stores if they have any.
   void ReloadProviders();
 
  private:
+  friend struct base::DefaultLazyInstanceTraits<CrosSettings>;
+
   // List of ChromeOS system settings providers.
   std::vector<CrosSettingsProvider*> providers_;
 
   // A map from settings names to a list of observers. Observers get fired in
   // the order they are added.
   typedef ObserverList<content::NotificationObserver> NotificationObserverList;
   typedef base::hash_map<std::string, NotificationObserverList*>
       SettingsObserverMap;
   SettingsObserverMap settings_observers_;
 
   CrosSettings();
   ~CrosSettings();
-  friend struct base::DefaultLazyInstanceTraits<CrosSettings>;
+
+  // Fires system setting change notification.
+  void FireObservers(const std::string& path);
 
   DISALLOW_COPY_AND_ASSIGN(CrosSettings);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CROS_SETTINGS_H_