More strict check for IBusPanelService.

chrome/browser/chromeos/input_method/ibus_controller_impl.cc

 // 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.
 
 #include "chrome/browser/chromeos/input_method/ibus_controller_impl.h"
 
 #include <algorithm>  // for std::reverse.
 #include <cstdio>
 #include <cstring>  // for std::strcmp.
 #include <set>
@@ skipping 467 matching lines @@
     g_signal_handlers_disconnect_by_func(
         ibus_,
         reinterpret_cast<gpointer>(G_CALLBACK(BusDisconnectedThunk)),
         this);
     g_signal_handlers_disconnect_by_func(
         ibus_,
         reinterpret_cast<gpointer>(G_CALLBACK(BusNameOwnerChangedThunk)),
         this);
 
     // Disconnect signals for the panel service as well.
-    IBusPanelService* ibus_panel_service = IBUS_PANEL_SERVICE(
-        g_object_get_data(G_OBJECT(ibus_), kPanelObjectKey));
+    // When Chrome is shutting down, g_object_get_data fails and returns NULL.
+    // TODO(nona): Investigate the reason of failure(crosbug.com/129142).
+    void* attached_data = g_object_get_data(G_OBJECT(ibus_), kPanelObjectKey);
+    if (!attached_data)
+      return;
+    if (!G_TYPE_CHECK_INSTANCE_TYPE(attached_data, IBUS_TYPE_PANEL_SERVICE))
+      return;
+    IBusPanelService* ibus_panel_service = IBUS_PANEL_SERVICE(attached_data);
     if (ibus_panel_service) {
       g_signal_handlers_disconnect_by_func(
           ibus_panel_service,
           reinterpret_cast<gpointer>(G_CALLBACK(FocusInThunk)),
           this);
       g_signal_handlers_disconnect_by_func(
           ibus_panel_service,
           reinterpret_cast<gpointer>(G_CALLBACK(RegisterPropertiesThunk)),
           this);
       g_signal_handlers_disconnect_by_func(
@@ skipping 608 matching lines @@
 
 // static
 bool IBusControllerImpl::FindAndUpdatePropertyForTesting(
     const chromeos::input_method::InputMethodProperty& new_prop,
     chromeos::input_method::InputMethodPropertyList* prop_list) {
   return FindAndUpdateProperty(new_prop, prop_list);
 }
 
 }  // namespace input_method
 }  // namespace chromeos