Initial CL for Data Saver (Flywheel) prompt when cellular network detected

chrome/browser/chromeos/status/data_promo_notification.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_CHROMEOS_STATUS_DATA_PROMO_NOTIFICATION_H_
 #define CHROME_BROWSER_CHROMEOS_STATUS_DATA_PROMO_NOTIFICATION_H_
 
 #include "base/basictypes.h"
 #include "base/memory/weak_ptr.h"
 #include "chromeos/network/network_state_handler_observer.h"
@@ skipping 16 matching lines @@
   DataPromoNotification();
   ~DataPromoNotification() override;
 
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  private:
   // NetworkStateHandlerObserver
   void NetworkPropertiesUpdated(const NetworkState* network) override;
   void DefaultNetworkChanged(const NetworkState* network) override;
 
-  // Shows 3G promo notification if needed.
-  void ShowOptionalMobileDataPromoNotification();
+  // Shows 3G promo notification if needed. |hotkey_debug| indicates that the
+  // NetworkPropertiesUpdated notification was generated by a debugging hotkey.
+  void ShowOptionalMobileDataPromoNotification(bool hotkey_debug);
+
+  // Show notification prompting user to install Data Saver extension.
+  bool ShowDataSaverNotification(bool hotkey_debug);
 
   // True if check for promo needs to be done, otherwise ignore it for the
   // current session.
   bool check_for_promo_;
 
   // Factory for delaying showing promo notification.
   base::WeakPtrFactory<DataPromoNotification> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DataPromoNotification);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_STATUS_DATA_PROMO_NOTIFICATION_H_