[ObjC ARC] Converts ios/chrome/browser/ui/ntp/recent_tabs:recent_tabs to ARC.

ios/chrome/browser/ui/ntp/recent_tabs/recent_tabs_panel_controller.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.
 
 #import "ios/chrome/browser/ui/ntp/recent_tabs/recent_tabs_panel_controller.h"
 
 #include <memory>
 
-#include "base/mac/scoped_nsobject.h"
 #include "components/browser_sync/profile_sync_service.h"
 #include "components/sessions/core/tab_restore_service.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "components/sync_sessions/open_tabs_ui_delegate.h"
 #include "components/sync_sessions/synced_session.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/sessions/ios_chrome_tab_restore_service_factory.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #include "ios/chrome/browser/sync/ios_chrome_profile_sync_service_factory.h"
 #include "ios/chrome/browser/sync/sync_setup_service.h"
 #include "ios/chrome/browser/sync/sync_setup_service_factory.h"
 #import "ios/chrome/browser/ui/ntp/recent_tabs/recent_tabs_bridges.h"
 #import "ios/chrome/browser/ui/ntp/recent_tabs/recent_tabs_table_view_controller.h"
 #import "ios/chrome/browser/ui/ntp/recent_tabs/synced_sessions_bridge.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface RecentTabsPanelController ()<SyncedSessionsObserver,
                                         RecentTabsTableViewControllerDelegate> {
   std::unique_ptr<synced_sessions::SyncedSessionsObserverBridge>
       _syncedSessionsObserver;
   std::unique_ptr<recent_tabs::ClosedTabsObserverBridge> _closedTabsObserver;
   SessionsSyncUserState _userState;
-  base::scoped_nsobject<RecentTabsTableViewController> _tableViewController;
+  RecentTabsTableViewController* _tableViewController;
   ios::ChromeBrowserState* _browserState;  // Weak.
 }
 
 // Return the user's current sign-in and chrome-sync state.
 - (SessionsSyncUserState)userSignedInState;
 // Utility functions for -userSignedInState so these can be mocked out
 // easily for unit tests.
 - (BOOL)isSignedIn;
 - (BOOL)isSyncTabsEnabled;
 - (BOOL)hasForeignSessions;
 - (BOOL)isSyncCompleted;
 // Reload the panel.
 - (void)refreshSessionsView;
 // Force a contact to the sync server to reload remote sessions.
 - (void)reloadSessionsData;
 
 @end
 
 // The controller for RecentTabs panel that is added to the NewTabPage
 // Instantiate a UITableView and a UITableViewController, and notifies the
 // UITableViewController of any signed in state change.
 @implementation RecentTabsPanelController
 
 // Property declared in NewTabPagePanelProtocol.
 @synthesize delegate = _delegate;
 
 - (instancetype)initWithLoader:(id<UrlLoader>)loader
                   browserState:(ios::ChromeBrowserState*)browserState {
-  return [self initWithController:[[[RecentTabsTableViewController alloc]
+  return [self initWithController:[[RecentTabsTableViewController alloc]
                                       initWithBrowserState:browserState
-                                                    loader:loader] autorelease]
+                                                    loader:loader]
                      browserState:browserState];
 }
 
 - (instancetype)initWithController:(RecentTabsTableViewController*)controller
                       browserState:(ios::ChromeBrowserState*)browserState {
   self = [super init];
   if (self) {
     DCHECK(controller);
     DCHECK(browserState);
     _browserState = browserState;
-    _tableViewController.reset([controller retain]);
+    _tableViewController = controller;
     [_tableViewController setDelegate:self];
     [self initObservers];
     [self reloadSessions];
   }
   return self;
 }
 
 - (void)dealloc {
   [_tableViewController setDelegate:nil];
   [self deallocObservers];
-  [super dealloc];
 }
 
 - (void)initObservers {
   if (!_syncedSessionsObserver) {
     _syncedSessionsObserver.reset(
         new synced_sessions::SyncedSessionsObserverBridge(self, _browserState));
   }
   if (!_closedTabsObserver) {
     _closedTabsObserver.reset(new recent_tabs::ClosedTabsObserverBridge(self));
     sessions::TabRestoreService* restoreService =
@@ skipping 137 matching lines @@
   [_tableViewController refreshUserState:[self userSignedInState]];
 }
 
 #pragma mark - RecentTabsTableViewControllerDelegate
 
 - (void)recentTabsTableViewContentMoved:(UITableView*)tableView {
   [self.delegate updateNtpBarShadowForPanelController:self];
 }
 
 @end