Expose scroll containers via accessibility APIs.

Source/modules/accessibility/AXObject.h

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * 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.
@@ skipping 657 matching lines @@
     virtual Element* anchorElement() const { return 0; }
     virtual Element* actionElement() const { return 0; }
     virtual Widget* widgetForAttachmentView() const { return 0; }
     String language() const;
     bool hasAttribute(const QualifiedName&) const;
     const AtomicString& getAttribute(const QualifiedName&) const;
 
     // Selected text.
     virtual PlainTextRange selectedTextRange() const { return PlainTextRange(); }
 
+    // Scrollable containers.
+    bool isScrollableContainer() const;
+    IntPoint scrollOffset() const;
+    IntPoint minimumScrollOffset() const;
+    IntPoint maximumScrollOffset() const;
+    void setScrollOffset(const IntPoint&) const;
+
     // Modify or take an action on an object.
     virtual void increment() { }
     virtual void decrement() { }
     bool performDefaultAction() const { return press(); }
     virtual bool press() const;
     // Make this object visible by scrolling as many nested scrollable views as needed.
     void scrollToMakeVisible() const;
     // Same, but if the whole object can't be made visible, try for this subrect, in local coordinates.
     void scrollToMakeVisibleWithSubFocus(const IntRect&) const;
     // Scroll this object to a given point in global coordinates of the top-level window.
@@ skipping 34 matching lines @@
     AccessibilityChildrenVector m_children;
     mutable bool m_haveChildren;
     AccessibilityRole m_role;
     AXObjectInclusion m_lastKnownIsIgnoredValue;
     LayoutRect m_explicitElementRect;
 
     virtual const AXObject* inheritsPresentationalRoleFrom() const { return 0; }
 
     // If this object itself scrolls, return its ScrollableArea.
     virtual ScrollableArea* getScrollableAreaIfScrollable() const { return 0; }
-    virtual void scrollTo(const IntPoint&) const { }
 
     AccessibilityRole buttonRoleType() const;
 
     unsigned getLengthForTextRange() const { return text().length(); }
 
     bool m_detached;
 
     mutable AXObject* m_parent;
 
     // The following cached attribute values (the ones starting with m_cached*)
@@ skipping 17 matching lines @@
     static bool includesARIAWidgetRole(const String&);
     static bool hasInteractiveARIAAttribute(const Element&);
 };
 
 #define DEFINE_AX_OBJECT_TYPE_CASTS(thisType, predicate) \
     DEFINE_TYPE_CASTS(thisType, AXObject, object, object->predicate, object.predicate)
 
 } // namespace blink
 
 #endif // AXObject_h