Gtk3: Silence deprecation warnings in //remoting

remoting/host/it2me/it2me_confirmation_dialog_linux.cc

Index: remoting/host/it2me/it2me_confirmation_dialog_linux.cc
diff --git a/remoting/host/it2me/it2me_confirmation_dialog_linux.cc b/remoting/host/it2me/it2me_confirmation_dialog_linux.cc
index a86a5b0ba956ccc1e1013f74d44da24164400817..ceb8c11571b1b3c1c2b56cf96574a4aa657fc7ac 100644
--- a/remoting/host/it2me/it2me_confirmation_dialog_linux.cc
+++ b/remoting/host/it2me/it2me_confirmation_dialog_linux.cc
@@ -124,7 +124,9 @@ void It2MeConfirmationDialogLinux::CreateWindow(
           remote_user_email);
   GtkWidget* text_label = gtk_label_new(base::UTF16ToUTF8(dialog_text).c_str());
   gtk_label_set_line_wrap(GTK_LABEL(text_label), true);
+  G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
   gtk_misc_set_padding(GTK_MISC(text_label), 12, 12);
+  G_GNUC_END_IGNORE_DEPRECATIONS;
 
   gtk_container_add(GTK_CONTAINER(content_area), text_label);
   gtk_widget_show_all(content_area);