Simplify and add caching for accessible bounding box calculation.

Source/core/accessibility/AccessibilityObject.cpp

 /*
  * Copyright (C) 2008, 2009, 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 552 matching lines @@
         return true;
 
     for (AccessibilityObject* axParent = parentObject(); axParent; axParent = axParent->parentObject()) {
         if (axParent->supportsARIALiveRegion())
             return true;
     }
 
     return false;
 }
 
+void AccessibilityObject::markCachedElementRectDirty() const
+{
+    for (unsigned i = 0; i < m_children.size(); ++i)
+        m_children[i].get()->markCachedElementRectDirty();
+}
+
 IntPoint AccessibilityObject::clickPoint()
 {
     LayoutRect rect = elementRect();
     return roundedIntPoint(LayoutPoint(rect.x() + rect.width() / 2, rect.y() + rect.height() / 2));
 }
 
 IntRect AccessibilityObject::boundingBoxForQuads(RenderObject* obj, const Vector<FloatQuad>& quads)
 {
     ASSERT(obj);
     if (!obj)
@@ skipping 197 matching lines @@
     if (Frame* f = actionElem->document()->frame())
         f->loader()->resetMultipleFormSubmissionProtection();
 
     UserGestureIndicator gestureIndicator(DefinitelyProcessingNewUserGesture);
     actionElem->accessKeyAction(true);
     return true;
 }
 
 void AccessibilityObject::scrollToMakeVisible() const
 {
-    IntRect objectRect = pixelSnappedIntRect(boundingBoxRect());
+    IntRect objectRect = pixelSnappedIntRect(elementRect());
     objectRect.setLocation(IntPoint());
     scrollToMakeVisibleWithSubFocus(objectRect);
 }
 
 // This is a 1-dimensional scroll offset helper function that's applied
 // separately in the horizontal and vertical directions, because the
 // logic is the same. The goal is to compute the best scroll offset
 // in order to make an object visible within a viewport.
 //
 // In case the whole object cannot fit, you can specify a
@@ skipping 67 matching lines @@
 {
     // Search up the parent chain until we find the first one that's scrollable.
     AccessibilityObject* scrollParent = parentObject();
     ScrollableArea* scrollableArea;
     for (scrollableArea = 0;
          scrollParent && !(scrollableArea = scrollParent->getScrollableAreaIfScrollable());
          scrollParent = scrollParent->parentObject()) { }
     if (!scrollableArea)
         return;
 
-    LayoutRect objectRect = boundingBoxRect();
+    LayoutRect objectRect = elementRect();
     IntPoint scrollPosition = scrollableArea->scrollPosition();
     IntRect scrollVisibleRect = scrollableArea->visibleContentRect();
 
     int desiredX = computeBestScrollOffset(
         scrollPosition.x(),
         objectRect.x() + subfocus.x(), objectRect.x() + subfocus.maxX(),
         objectRect.x(), objectRect.maxX(),
         0, scrollVisibleRect.width());
     int desiredY = computeBestScrollOffset(
         scrollPosition.y(),
@@ skipping 24 matching lines @@
     // next innermost object to the given point.
     int offsetX = 0, offsetY = 0;
     IntPoint point = globalPoint;
     size_t levels = objects.size() - 1;
     for (size_t i = 0; i < levels; i++) {
         const AccessibilityObject* outer = objects[i];
         const AccessibilityObject* inner = objects[i + 1];
 
         ScrollableArea* scrollableArea = outer->getScrollableAreaIfScrollable();
 
-        LayoutRect innerRect = inner->isAccessibilityScrollView() ? inner->parentObject()->boundingBoxRect() : inner->boundingBoxRect();
+        LayoutRect innerRect = inner->isAccessibilityScrollView() ? inner->parentObject()->elementRect() : inner->elementRect();
         LayoutRect objectRect = innerRect;
         IntPoint scrollPosition = scrollableArea->scrollPosition();
 
         // Convert the object rect into local coordinates.
         objectRect.move(offsetX, offsetY);
         if (!outer->isAccessibilityScrollView())
             objectRect.move(scrollPosition.x(), scrollPosition.y());
 
         int desiredX = computeBestScrollOffset(
             0,
@@ skipping 381 matching lines @@
 
     for (AccessibilityObject* object = parentObject(); object; object = object->parentObject()) {
         if (equalIgnoringCase(object->getAttribute(aria_hiddenAttr), "true"))
             return true;
     }
 
     return false;
 }
 
 } // namespace WebCore