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

chrome/browser/chromeos/device_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_CHROMEOS_DEVICE_SETTINGS_PROVIDER_H_
 #define CHROME_BROWSER_CHROMEOS_DEVICE_SETTINGS_PROVIDER_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 16 matching lines @@
 }
 
 namespace chromeos {
 
 class OwnershipService;
 
 // CrosSettingsProvider implementation that works with SignedSettings.
 class DeviceSettingsProvider : public CrosSettingsProvider,
                                public content::NotificationObserver {
  public:
-  DeviceSettingsProvider();
+  explicit DeviceSettingsProvider(const NotifyObserversCallback& notify_cb);
   virtual ~DeviceSettingsProvider();
 
   // CrosSettingsProvider implementation.
   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;
 
  private:
@@ skipping 74 matching lines @@
   PrefValueMap values_cache_;
 
   friend class SignedSettingsHelper;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceSettingsProvider);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_DEVICE_SETTINGS_PROVIDER_H_