Update browser cache of accessibility tree on renderer sub-tree changes....

chrome/browser/browser_accessibility_win.h

Index: chrome/browser/browser_accessibility_win.h
===================================================================
--- chrome/browser/browser_accessibility_win.h	(revision 57122)
+++ chrome/browser/browser_accessibility_win.h	(working copy)
@@ -67,6 +67,10 @@
   // Return true if this object is equal to or a descendant of |ancestor|.
   bool IsDescendantOf(BrowserAccessibility* ancestor);
 
+  // Returns the parent of this object, or NULL if it's the BrowserAccessibility
+  // root.
+  BrowserAccessibility* GetParent();
+
   // Return the previous sibling of this object, or NULL if it's the first
   // child of its parent.
   BrowserAccessibility* GetPreviousSibling();
@@ -75,9 +79,15 @@
   // of its parent.
   BrowserAccessibility* GetNextSibling();
 
+  // Replace a child BrowserAccessibility object. Used when updating the
+  // accessibility tree.
+  void ReplaceChild(
+      const BrowserAccessibility* old_acc, BrowserAccessibility* new_acc);
+
   // Accessors
   LONG child_id() const { return child_id_; }
   int32 renderer_id() const { return renderer_id_; }
+  LONG index_in_parent() const { return index_in_parent_; }
 
   // Add one to the reference count and return the same object. Always
   // use this method when returning a BrowserAccessibility object as