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

ui/accessibility/platform/ax_platform_node_win.h

Index: ui/accessibility/platform/ax_platform_node_win.h
diff --git a/ui/accessibility/platform/ax_platform_node_win.h b/ui/accessibility/platform/ax_platform_node_win.h
index eb747ed4d0b1a02aa2ff0cafb266ed53205f3f61..4d84e8d656de375375fd78cac902ca7f282b60b0 100644
--- a/ui/accessibility/platform/ax_platform_node_win.h
+++ b/ui/accessibility/platform/ax_platform_node_win.h
@@ -54,11 +54,11 @@ AXPlatformNodeWin
   ~AXPlatformNodeWin() override;
 
   // AXPlatformNode overrides.
-  void Destroy() override;
   gfx::NativeViewAccessible GetNativeViewAccessible() override;
   void NotifyAccessibilityEvent(ui::AXEvent event_type) override;
 
   // AXPlatformNodeBase overrides.
+  void Destroy() override;
   int GetIndexInParent() override;
 
   //
@@ -267,6 +267,9 @@ AXPlatformNodeWin
  protected:
   AXPlatformNodeWin();
 
+  // AXPlatformNodeBase overrides.
+  void Dispose() override;
+
  private:
   bool IsValidId(const VARIANT& child) const;
   int MSAARole();