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

chrome/browser/ui/webui/options/chromeos/system_settings_provider.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_UI_WEBUI_OPTIONS_CHROMEOS_SYSTEM_SETTINGS_PROVIDER_H_
 #define CHROME_BROWSER_UI_WEBUI_OPTIONS_CHROMEOS_SYSTEM_SETTINGS_PROVIDER_H_
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/string16.h"
 #include "chrome/browser/chromeos/cros_settings_provider.h"
 #include "chrome/browser/chromeos/system/timezone_settings.h"
 #include "third_party/icu/public/i18n/unicode/timezone.h"
 
 namespace base {
 class Value;
 class ListValue;
 class StringValue;
 }
 
 namespace chromeos {
 
 class SystemSettingsProvider : public CrosSettingsProvider,
                                public system::TimezoneSettings::Observer {
  public:
-  SystemSettingsProvider();
+  explicit SystemSettingsProvider(const NotifyObserversCallback& notify_cb);
   virtual ~SystemSettingsProvider();
 
   // CrosSettingsProvider overrides.
   virtual const base::Value* Get(const std::string& path) const OVERRIDE;
   virtual bool GetTrusted(const std::string& path,
                           const base::Closure& callback) OVERRIDE;
   virtual bool HandlesSetting(const std::string& path) const OVERRIDE;
   virtual void Reload() OVERRIDE;
 
   // Overridden from TimezoneSettings::Observer:
@@ skipping 29 matching lines @@
   std::vector<icu::TimeZone*> timezones_;
 
   scoped_ptr<base::Value> timezone_value_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemSettingsProvider);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_OPTIONS_CHROMEOS_SYSTEM_SETTINGS_PROVIDER_H_