Add a receiver interface to RemovableStorageNotifications.

chrome/browser/system_monitor/removable_device_notifications_chromeos.cc

Index: chrome/browser/system_monitor/removable_device_notifications_chromeos.cc
diff --git a/chrome/browser/system_monitor/removable_device_notifications_chromeos.cc b/chrome/browser/system_monitor/removable_device_notifications_chromeos.cc
index 2b0072bea5f81ff70949d802ae0200d1f37f884d..21cc14d7c0c0f28a93c1d536a0628ec3f2ab8ed2 100644
--- a/chrome/browser/system_monitor/removable_device_notifications_chromeos.cc
+++ b/chrome/browser/system_monitor/removable_device_notifications_chromeos.cc
@@ -156,7 +156,7 @@ void RemovableDeviceNotificationsCros::OnMountEvent(
       MountMap::iterator it = mount_map_.find(mount_info.mount_path);
       if (it == mount_map_.end())
         return;
-      ProcessDetach(it->second.storage_info.device_id);
+      receiver_->ProcessDetach(it->second.storage_info.device_id);
       mount_map_.erase(it);
       break;
     }
@@ -246,10 +246,10 @@ void RemovableDeviceNotificationsCros::AddMountedPathOnUIThread(
       storage_size_in_bytes
   };
   mount_map_.insert(std::make_pair(mount_info.mount_path, object_info));
-  ProcessAttach(
+  receiver_->ProcessAttach(StorageInfo(
       device_id,
       chrome::GetDisplayNameForDevice(storage_size_in_bytes, device_label),
-      mount_info.mount_path);
+      mount_info.mount_path));
 }
 
 }  // namespace chromeos