Revert "[ios] Ensure proper shutdown of Chrome on iOS."

ios/chrome/browser/ui/main/browser_view_wrangler.mm

 // Copyright 2016 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/main/browser_view_wrangler.h"
 
 #include "base/mac/objc_property_releaser.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #import "ios/chrome/browser/browsing_data/browsing_data_removal_controller.h"
 #include "ios/chrome/browser/browsing_data/ios_chrome_browsing_data_remover.h"
 #include "ios/chrome/browser/crash_report/crash_report_helper.h"
 #import "ios/chrome/browser/device_sharing/device_sharing_manager.h"
 #import "ios/chrome/browser/physical_web/start_physical_web_discovery.h"
 #import "ios/chrome/browser/sessions/session_ios.h"
 #import "ios/chrome/browser/sessions/session_service_ios.h"
 #import "ios/chrome/browser/sessions/session_window_ios.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/tabs/tab_model.h"
 #import "ios/chrome/browser/tabs/tab_model_observer.h"
 #import "ios/chrome/browser/ui/browser_view_controller.h"
 #import "ios/chrome/browser/ui/browser_view_controller_dependency_factory.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 
 @interface BrowserViewWrangler ()<TabModelObserver> {
   ios::ChromeBrowserState* _browserState;
   __unsafe_unretained id<TabModelObserver> _tabModelObserver;
-  BOOL _isShutdown;
 
   base::mac::ObjCPropertyReleaser _propertyReleaser_BrowserViewWrangler;
 }
 
 // Responsible for maintaining all state related to sharing to other devices.
 // Redeclared readwrite from the readonly declaration in the Testing interface.
 @property(nonatomic, retain, readwrite)
     DeviceSharingManager* deviceSharingManager;
 
 // Creates a new autoreleased tab model for |browserState|; if |empty| is NO,
@@ skipping 35 matching lines @@
   }
   return self;
 }
 
 - (instancetype)init {
   NOTREACHED();
   return nil;
 }
 
 - (void)dealloc {
-  DCHECK(_isShutdown) << "-shutdown must be called before -dealloc";
+  if (_tabModelObserver) {
+    [_mainTabModel removeObserver:_tabModelObserver];
+    [_otrTabModel removeObserver:_tabModelObserver];
+  }
+  [_mainTabModel removeObserver:self];
+  [_otrTabModel removeObserver:self];
+
+  // Stop URL monitoring of the main tab model.
+  ios_internal::breakpad::StopMonitoringURLsForTabModel(_mainTabModel);
+
+  // Stop Breakpad state monitoring of both tab models (if necessary).
+  ios_internal::breakpad::StopMonitoringTabStateForTabModel(_mainTabModel);
+  ios_internal::breakpad::StopMonitoringTabStateForTabModel(_otrTabModel);
+
+  // Normally other objects will take care of unhooking the tab models from
+  // the browser state, but this code should ensure that it happens regardless.
+  [_mainTabModel browserStateDestroyed];
+  [_otrTabModel browserStateDestroyed];
+
   [super dealloc];
 }
 
 #pragma mark - BrowserViewInformation property implementations
 
 - (BrowserViewController*)mainBVC {
   if (!_mainBVC) {
     // |_browserState| should always be set before trying to create
     // |_mainBVC|.
     DCHECK(_browserState);
@@ skipping 162 matching lines @@
   // be immediately deleted.
   self.otrTabModel = [self buildOtrTabModel:YES];
   DCHECK(![self.otrTabModel count]);
   DCHECK(_browserState->HasOffTheRecordChromeBrowserState());
 
   if (otrBVCIsCurrent) {
     _currentBVC = self.otrBVC;
   }
 }
 
-- (void)shutdown {
-  DCHECK(!_isShutdown);
-  _isShutdown = YES;
-
-  if (_tabModelObserver) {
-    [_mainTabModel removeObserver:_tabModelObserver];
-    [_otrTabModel removeObserver:_tabModelObserver];
-    _tabModelObserver = nil;
-  }
-
-  [_mainTabModel removeObserver:self];
-  [_otrTabModel removeObserver:self];
-
-  // Stop URL monitoring of the main tab model.
-  ios_internal::breakpad::StopMonitoringURLsForTabModel(_mainTabModel);
-
-  // Stop Breakpad state monitoring of both tab models (if necessary).
-  ios_internal::breakpad::StopMonitoringTabStateForTabModel(_mainTabModel);
-  ios_internal::breakpad::StopMonitoringTabStateForTabModel(_otrTabModel);
-
-  // Normally other objects will take care of unhooking the tab models from
-  // the browser state, but this code should ensure that it happens regardless.
-  [_mainTabModel browserStateDestroyed];
-  [_otrTabModel browserStateDestroyed];
-
-  [_mainBVC shutdown];
-  [_otrBVC shutdown];
-  self.mainBVC = nil;
-  self.otrBVC = nil;
-
-  _browserState = nullptr;
-}
-
 #pragma mark - Internal methods
 
 - (TabModel*)buildOtrTabModel:(BOOL)empty {
   DCHECK(_browserState);
   // Ensure that the OTR ChromeBrowserState is created.
   ios::ChromeBrowserState* otrBrowserState =
       _browserState->GetOffTheRecordChromeBrowserState();
   DCHECK(otrBrowserState);
   return [self tabModelForBrowserState:otrBrowserState empty:empty];
 }
@@ skipping 33 matching lines @@
                                     tabModel:(TabModel*)tabModel {
   base::scoped_nsobject<BrowserViewControllerDependencyFactory> factory(
       [[BrowserViewControllerDependencyFactory alloc]
           initWithBrowserState:browserState]);
   return [[[BrowserViewController alloc] initWithTabModel:tabModel
                                              browserState:browserState
                                         dependencyFactory:factory] autorelease];
 }
 
 @end