Change scoped_ptr<FrameTreeNode> to FrameTreeNode*

content/browser/frame_host/frame_tree.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 CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 33 matching lines @@
   // RenderFrameHostManagers.
   // TODO(creis): This set of delegates will change as we move things to
   // Navigator.
   FrameTree(Navigator* navigator,
             RenderFrameHostDelegate* render_frame_delegate,
             RenderViewHostDelegate* render_view_delegate,
             RenderWidgetHostDelegate* render_widget_delegate,
             RenderFrameHostManager::Delegate* manager_delegate);
   ~FrameTree();
 
-  FrameTreeNode* root() const { return root_.get(); }
+  FrameTreeNode* root() const { return root_; }
 
   // Returns the FrameTreeNode with the given |frame_tree_node_id| if it is part
   // of this FrameTree.
   FrameTreeNode* FindByID(int frame_tree_node_id);
 
   // Returns the FrameTreeNode with the given renderer-specific |routing_id|.
   FrameTreeNode* FindByRoutingID(int process_id, int routing_id);
 
   // Returns the first frame in this tree with the given |name|, or the main
   // frame if |name| is empty.
@@ skipping 108 matching lines @@
   // the map will be cleared before we delete the RenderFrameHosts in the tree.
   RenderViewHostMap render_view_host_map_;
 
   // Map of SiteInstance ID to RenderViewHosts that are pending shutdown. The
   // renderers of these RVH are currently executing the unload event in
   // background. When the SwapOutACK is received, they will be deleted. In the
   // meantime, they are kept in this map, as they should not be reused (part of
   // their state is already gone away).
   RenderViewHostMultiMap render_view_host_pending_shutdown_map_;
 
-  scoped_ptr<FrameTreeNode> root_;
+  // This is an owned ptr to the root frame tree node, which never changes over

[nasko, 2015/10/05 17:19:30]

nit: s/frame tree node/FrameTreeNode/

[ncarter (slow), 2015/10/05 17:23:22]

Done.

+  // the lifetime of the tree. It is not a scoped_ptr because we need the
+  // pointer to remain valid even while the frame tree node is being destroyed,
+  // since it's common for a node to test whether it's the root node.
+  FrameTreeNode* root_;
 
   int focused_frame_tree_node_id_;
 
   base::Callback<void(RenderFrameHost*)> on_frame_removed_;
 
   // Overall load progress.
   double load_progress_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTree);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_