Keep track of fixed positioning in accessibility tree.

third_party/WebKit/Source/modules/accessibility/AXSpinButton.h

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 55 matching lines @@
   ~AXSpinButtonPart() override {}
   void SetIsIncrementor(bool value) { is_incrementor_ = value; }
 
  private:
   explicit AXSpinButtonPart(AXObjectCacheImpl&);
   bool is_incrementor_ : 1;
 
   bool Press() override;
   AccessibilityRole RoleValue() const override { return kButtonRole; }
   bool IsSpinButtonPart() const override { return true; }
-  void GetRelativeBounds(AXObject** out_container,
-                         FloatRect& out_bounds_in_container,
-                         SkMatrix44& out_container_transform) const override;
+  bool GetSimpleRelativeBounds(
+      AXObject** out_container,
+      FloatRect& out_bounds_in_container) const override;
 };
 
 DEFINE_AX_OBJECT_TYPE_CASTS(AXSpinButton, IsNativeSpinButton());
 DEFINE_AX_OBJECT_TYPE_CASTS(AXSpinButtonPart, IsSpinButtonPart());
 
 }  // namespace blink
 
 #endif  // AXSpinButton_h