Use relative bounding boxes throughout Chrome accessibility

ui/accessibility/ax_node.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_ACCESSIBILITY_AX_NODE_H_
 #define UI_ACCESSIBILITY_AX_NODE_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 26 matching lines @@
   // Get the child at the given index.
   AXNode* ChildAtIndex(int index) const { return children_[index]; }
 
   // Set the node's accessibility data. This may be done during initial
   // initialization or later when the node data changes.
   void SetData(const AXNodeData& src);
 
   // Update this node's location. This is separate from SetData just because
   // changing only the location is common and should be more efficient than
   // re-copying all of the data.
-  void SetLocation(const gfx::RectF& new_location);
+  //
+  // The node's location is stored as a relative bounding box, the ID of
+  // the element it's relative to, and an optional transformation matrix.
+  // See ax_node_data.h for details.
+  void SetLocation(int offset_container_id,
+                   const gfx::RectF& location,
+                   gfx::Transform* transform);
 
   // Set the index in parent, for example if siblings were inserted or deleted.
   void SetIndexInParent(int index_in_parent);
 
   // Swap the internal children vector with |children|. This instance
   // now owns all of the passed children.
   void SwapChildren(std::vector<AXNode*>& children);
 
   // This is called when the AXTree no longer includes this node in the
   // tree. Reference counting is used on some platforms because the
   // operating system may hold onto a reference to an AXNode
   // object even after we're through with it, so this may decrement the
   // reference count and clear out the object's data.
   void Destroy();
 
   // Return true if this object is equal to or a descendant of |ancestor|.
   bool IsDescendantOf(AXNode* ancestor);
 
  private:
   int index_in_parent_;
   AXNode* parent_;
   std::vector<AXNode*> children_;
   AXNodeData data_;
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_AX_NODE_H_