Load offline page if reading list entry takes more than 1s to load.

ios/web/navigation/navigation_item_impl.mm

 // Copyright 2014 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.
 
 #include "ios/web/navigation/navigation_item_impl.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
@@ skipping 33 matching lines @@
       should_skip_resubmit_data_confirmation_(false),
       is_renderer_initiated_(false),
       is_unsafe_(false),
       facade_delegate_(nullptr) {
 }
 
 NavigationItemImpl::~NavigationItemImpl() {
 }
 
 NavigationItemImpl::NavigationItemImpl(const NavigationItemImpl& item)
-    : unique_id_(item.unique_id_),
+    : extra_data_(item.extra_data_),
+      unique_id_(item.unique_id_),
       url_(item.url_),
       referrer_(item.referrer_),
       virtual_url_(item.virtual_url_),
       title_(item.title_),
       page_display_state_(item.page_display_state_),
       transition_type_(item.transition_type_),
       favicon_(item.favicon_),
       ssl_(item.ssl_),
       timestamp_(item.timestamp_),
       is_overriding_user_agent_(item.is_overriding_user_agent_),
@@ skipping 200 matching lines @@
 void NavigationItemImpl::ResetHttpRequestHeaders() {
   http_request_headers_.reset();
 }
 
 void NavigationItemImpl::ResetForCommit() {
   // Any state that only matters when a navigation item is pending should be
   // cleared here.
   set_is_renderer_initiated(false);
 }
 
+NSDictionary* NavigationItemImpl::GetExtraData() const {
+  return extra_data_;
+}
+
 }  // namespace web