Linux Aura accessibility is enabled only on GNOME desktops

ui/accessibility/platform/atk_util_auralinux.h

 // Copyright 2015 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 UI_ACCESSIBILITY_AX_UTIL_AURALINUX_H_
 #define UI_ACCESSIBILITY_AX_UTIL_AURALINUX_H_
 
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "ui/accessibility/ax_export.h"
 
+namespace base {
+class Thread;
+}
+
 namespace ui {
 
 // This singleton class initializes ATK (accessibility toolkit) and
 // registers an implementation of the AtkUtil class, a global class that
 // every accessible application needs to register once.
 class AtkUtilAuraLinux {
  public:
   // Get the single instance of this class.
   static AtkUtilAuraLinux* GetInstance();
 
   AtkUtilAuraLinux();
   virtual ~AtkUtilAuraLinux();
-
  private:
   friend struct DefaultSingletonTraits<AtkUtilAuraLinux>;
+
+  void CheckIfAccessibilityIsEnabled();
+  void CheckPlatformAccessibilitySupport();
+  void OnStopAccessibilityThread();
+
+#if defined(USE_GCONF) || defined(USE_DBUS)
+  bool is_enabled_;
+  scoped_ptr<base::Thread> accessibility_init_thread_;
+#endif
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_AX_UTIL_AURALINUX_H_