Simplify and add caching for accessible bounding box calculation.

Source/core/accessibility/AccessibilitySlider.cpp

 /*
  * Copyright (C) 2009 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 29 matching lines @@
 AccessibilitySlider::AccessibilitySlider(RenderObject* renderer)
     : AccessibilityRenderObject(renderer)
 {
 }
 
 PassRefPtr<AccessibilitySlider> AccessibilitySlider::create(RenderObject* renderer)
 {
     return adoptRef(new AccessibilitySlider(renderer));
 }
 
-AccessibilityOrientation AccessibilitySlider::orientation() const
+AccessibilityOrientation AccessibilitySlider::orientation()
 {
     // Default to horizontal in the unknown case.
     if (!m_renderer)
         return AccessibilityOrientationHorizontal;
     
     RenderStyle* style = m_renderer->style();
     if (!style)
         return AccessibilityOrientationHorizontal;
     
     ControlPart styleAppearance = style->appearance();
@@ skipping 31 matching lines @@
         cache->remove(thumb->axObjectID());
     else
         m_children.append(thumb);
 }
 
 const AtomicString& AccessibilitySlider::getAttribute(const QualifiedName& attribute) const
 {
     return element()->getAttribute(attribute);
 }
     
-AccessibilityObject* AccessibilitySlider::elementAccessibilityHitTest(const IntPoint& point) const
+AccessibilityObject* AccessibilitySlider::elementAccessibilityHitTest(const IntPoint& point)
 {
     if (m_children.size()) {
         ASSERT(m_children.size() == 1);
         if (m_children[0]->elementRect().contains(point))
             return m_children[0].get();
     }
     
     return axObjectCache()->getOrCreate(m_renderer);
 }
 
@@ skipping 33 matching lines @@
 
 AccessibilitySliderThumb::AccessibilitySliderThumb()
 {
 }
 
 PassRefPtr<AccessibilitySliderThumb> AccessibilitySliderThumb::create()
 {
     return adoptRef(new AccessibilitySliderThumb());
 }
     
-LayoutRect AccessibilitySliderThumb::elementRect() const
+LayoutRect AccessibilitySliderThumb::elementRect()
 {
     if (!m_parent)
         return LayoutRect();
     
     RenderObject* sliderRenderer = m_parent->renderer();
     if (!sliderRenderer || !sliderRenderer->isSlider())
         return LayoutRect();
     return sliderThumbElementOf(sliderRenderer->node())->boundingBox();
 }
 
 bool AccessibilitySliderThumb::computeAccessibilityIsIgnored() const
 {
     return accessibilityIsIgnoredByDefault();
 }
 
 } // namespace WebCore