Fix crash bug http://crbug.com/725594

content/browser/frame_host/interstitial_page_impl.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_INTERSTITIAL_PAGE_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 247 matching lines @@
   ActionState action_taken_;
 
   // The RenderViewHost displaying the interstitial contents.  This is valid
   // until Hide is called, at which point it will be set to NULL, signifying
   // that shutdown has started.
   // TODO(creis): This is now owned by the FrameTree.  We should route things
   // through the tree's root RenderFrameHost instead.
   RenderViewHostImpl* render_view_host_;
 
   // The frame tree structure of the current page.
-  FrameTree frame_tree_;
+  std::unique_ptr<FrameTree> frame_tree_;
 
   // The IDs for the Render[View|Process]Host hidden by this interstitial.
   int original_child_id_;
   int original_rvh_id_;
 
   // Whether or not we should change the title of the contents when hidden (to
   // revert it to its original value).
   bool should_revert_web_contents_title_;
 
   // Whether the ResourceDispatcherHost has been notified to cancel/resume the
@@ skipping 22 matching lines @@
   scoped_refptr<SessionStorageNamespace> session_storage_namespace_;
 
   base::WeakPtrFactory<InterstitialPageImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InterstitialPageImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_