Adds ability for tree model to reorder its children. I'm going to use...

chrome/views/tree_view.h

 // Copyright (c) 2006-2008 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 CHROME_VIEWS_TREE_VIEW_H__
 #define CHROME_VIEWS_TREE_VIEW_H__
 
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 87 matching lines @@
   // TreeModelObserver methods. Don't call these directly, instead your model
   // should notify the observer TreeView adds to it.
   virtual void TreeNodesAdded(TreeModel* model,
                               TreeModelNode* parent,
                               int start,
                               int count);
   virtual void TreeNodesRemoved(TreeModel* model,
                                 TreeModelNode* parent,
                                 int start,
                                 int count);
+  virtual void TreeNodeChildrenReordered(TreeModel* model,
+                                         TreeModelNode* parent);
   virtual void TreeNodeChanged(TreeModel* model, TreeModelNode* node);
 
   // Sets the controller, which may be null. TreeView does not take ownership
   // of the controller.
   void SetController(TreeViewController* controller) {
     controller_ = controller;
   }
 
   // Sets whether enter is processed when not editing. If true, enter will
   // expand/collapse the node. If false, enter is passed to the focus manager
@@ skipping 109 matching lines @@
     DCHECK(id_to_details_map_.find(id) != id_to_details_map_.end());
     return id_to_details_map_[id];
   }
 
   // Returns the NodeDetails by HTREEITEM.
   NodeDetails* GetNodeDetailsByTreeItem(HTREEITEM tree_item);
 
   // Creates the image list to use for the tree.
   HIMAGELIST CreateImageList();
 
+  // Returns the HTREEITEM for |node|. This is intended to be called when a
+  // model mutation event occur with |node| as the parent. This returns null
+  // if the user has never expanded |node| or all of its parents.
+  HTREEITEM GetTreeItemForNodeDuringMutation(TreeModelNode* node);
+
   // The window function installed on the treeview.
   static LRESULT CALLBACK TreeWndProc(HWND window,
                                       UINT message,
                                       WPARAM w_param,
                                       LPARAM l_param);
 
   // Handle to the tree window.
   HWND tree_view_;
 
   // The model, may be null.
@@ skipping 42 matching lines @@
   bool has_custom_icons_;
 
   HIMAGELIST image_list_;
 
   DISALLOW_COPY_AND_ASSIGN(TreeView);
 };
 
 }  // namespace views
 
 #endif  // CHROME_VIEWS_TREE_VIEW_H__