Oilpan: Prepare moving AccessibilityText to the heap

Source/modules/accessibility/AXNodeObject.h

 /*
  * Copyright (C) 2012, Google 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 194 matching lines @@
     virtual int posInSet() const override;
     virtual int setSize() const override;
 
     // Aria-owns.
     void computeAriaOwnsChildren(Vector<AXObject*>& ownedChildren);
 
 private:
     Node* m_node;
 
     String alternativeTextForWebArea() const;
-    void alternativeText(Vector<AccessibilityText>&) const;
-    void ariaLabeledByText(Vector<AccessibilityText>&) const;
+    void alternativeText(WillBeHeapVector<OwnPtrWillBeMember<AccessibilityText>>&) const;
+    void ariaLabeledByText(WillBeHeapVector<OwnPtrWillBeMember<AccessibilityText>>&) const;
     float stepValueForRange() const;
     AXObject* findChildWithTagName(const HTMLQualifiedName&) const;
     bool isDescendantOfElementType(const HTMLQualifiedName& tagName) const;
 };
 
 DEFINE_AX_OBJECT_TYPE_CASTS(AXNodeObject, isAXNodeObject());
 
 } // namespace blink
 
 #endif // AXNodeObject_h