Appropriate handling for Cellular First devices.

chromeos/dbus/fake_update_engine_client.h

Index: chromeos/dbus/fake_update_engine_client.h
diff --git a/chromeos/dbus/fake_update_engine_client.h b/chromeos/dbus/fake_update_engine_client.h
index a1aa3aa8cbbf152dd3e8b58943ab6e2f30a18241..2d9db4cca6bf529c710ba02be557714c4bd01519 100644
--- a/chromeos/dbus/fake_update_engine_client.h
+++ b/chromeos/dbus/fake_update_engine_client.h
@@ -36,6 +36,8 @@ class FakeUpdateEngineClient : public UpdateEngineClient {
   void GetChannel(bool get_current_channel,
                   const GetChannelCallback& callback) override;
   void GetEolStatus(const GetEolStatusCallback& callback) override;
+  void SetUpdateOverCellularPermission(bool allowed,
+                                       const base::Closure& callback) override;
 
   // Pushes UpdateEngineClient::Status in the queue to test changing status.
   // GetLastStatus() returns the status set by this method in FIFO order.