Clean up code and logic related to platform accessibility node destruction.

ui/accessibility/platform/ax_platform_node_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_PLATFORM_NODE_AURALINUX_H_
 #define UI_ACCESSIBILITY_AX_PLATFORM_NODE_AURALINUX_H_
 
 #include <atk/atk.h>
 
 #include "base/macros.h"
@@ skipping 27 matching lines @@
   void GetExtents(gint* x, gint* y, gint* width, gint* height,
                   AtkCoordType coord_type);
   void GetPosition(gint* x, gint* y, AtkCoordType coord_type);
   void GetSize(gint* width, gint* height);
 
   void SetExtentsRelativeToAtkCoordinateType(
       gint* x, gint* y, gint* width, gint* height,
       AtkCoordType coord_type);
 
   // AXPlatformNode overrides.
-  void Destroy() override;
   gfx::NativeViewAccessible GetNativeViewAccessible() override;
   void NotifyAccessibilityEvent(ui::AXEvent event_type) override;
 
   // AXPlatformNodeBase overrides.
   void Init(AXPlatformNodeDelegate* delegate) override;
   int GetIndexInParent() override;
 
  private:
   ~AXPlatformNodeAuraLinux() override;
 
   // We own a reference to this ref-counted object.
   AtkObject* atk_object_;
 
   // The root-level Application object that's the parent of all
   // top-level windows.
   static AXPlatformNode* application_;
 
   DISALLOW_COPY_AND_ASSIGN(AXPlatformNodeAuraLinux);
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_AX_PLATFORM_NODE_AURALINUX_H_