[ios] Remove TabModel cleanup from -dealloc to -browserStateDestroyed.

ios/chrome/browser/tabs/tab.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.
 
 #import "ios/chrome/browser/tabs/tab.h"
 
 #import <CoreLocation/CoreLocation.h>
 #import <UIKit/UIKit.h>
 
 #include <utility>
@@ skipping 994 matching lines @@
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 
   [passwordController_ detach];
   passwordController_ = nil;
   _tabInfoBarObserver.reset();
 
   _faviconDriverObserverBridge.reset();
   [_openInController detachFromWebController];
   _openInController = nil;
   [_autofillController detachFromWebState];
+  _autofillController = nil;
   [_suggestionController detachFromWebState];
+  _suggestionController = nil;
   if (_fullScreenController)
     [self.webController removeObserver:_fullScreenController];
   [_fullScreenController invalidate];
   _fullScreenController = nil;
   if (_overscrollActionsController)
     [self.webController removeObserver:_overscrollActionsController];
   [_overscrollActionsController invalidate];
   _overscrollActionsController = nil;
   [readerModeController_ detachFromWebState];
   readerModeController_ = nil;
@@ skipping 873 matching lines @@
 
 - (TabModel*)parentTabModel {
   return _parentTabModel;
 }
 
 - (FormInputAccessoryViewController*)inputAccessoryViewController {
   return _inputAccessoryViewController;
 }
 
 @end