Ensure History > Recent Tabs restore preserves window disposition.

ios/chrome/browser/sessions/tab_restore_service_delegate_impl_ios.mm

 // Copyright 2012 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/chrome/browser/sessions/tab_restore_service_delegate_impl_ios.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 50 matching lines @@
 sessions::LiveTab* TabRestoreServiceDelegateImplIOS::GetLiveTabAt(
     int index) const {
   return nullptr;
 }
 
 sessions::LiveTab* TabRestoreServiceDelegateImplIOS::GetActiveLiveTab() const {
   return nullptr;
 }
 
 bool TabRestoreServiceDelegateImplIOS::IsTabPinned(int index) const {
+  // Not supported by iOS.
   return false;
 }
 
+const gfx::Rect TabRestoreServiceDelegateImplIOS::GetRestoredBounds() const {
+  // Not supported by iOS.
+  return gfx::Rect();
+}
+
+ui::WindowShowState TabRestoreServiceDelegateImplIOS::GetRestoredState() const {
+  // Not supported by iOS.
+  return ui::SHOW_STATE_NORMAL;
+}
+
+std::string TabRestoreServiceDelegateImplIOS::GetWorkspace() const {
+  // Not supported by iOS.
+  return std::string();
+}
+
 sessions::LiveTab* TabRestoreServiceDelegateImplIOS::AddRestoredTab(
     const std::vector<sessions::SerializedNavigationEntry>& navigations,
     int tab_index,
     int selected_navigation,
     const std::string& extension_app_id,
     bool select,
     bool pin,
     bool from_last_session,
     const sessions::PlatformSpecificTabData* tab_platform_data,
     const std::string& user_agent_override) {
@@ skipping 31 matching lines @@
   Tab* tab = tab_model().currentTab;
   [tab replaceHistoryWithNavigations:navigations
                         currentIndex:selected_navigation];
   return nullptr;
 }
 
 void TabRestoreServiceDelegateImplIOS::CloseTab() {
   WebStateList* web_state_list = [tab_model() webStateList];
   web_state_list->CloseWebStateAt(web_state_list->active_index());
 }