Zero-out crw_web_controller's container view delegate in dealloc.

ios/web/web_state/ui/crw_web_controller_container_view.h

 // Copyright 2015 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.
 
 #ifndef IOS_WEB_WEB_STATE_UI_CRW_WEB_CONTROLLER_CONTAINER_VIEW_H_
 #define IOS_WEB_WEB_STATE_UI_CRW_WEB_CONTROLLER_CONTAINER_VIEW_H_
 
 #import <UIKit/UIKit.h>
 
 #include "ios/web/public/web_state/ui/crw_content_view.h"
@@ skipping 21 matching lines @@
 @interface CRWWebControllerContainerView : UIView
 
 #pragma mark Content Views
 // The web view content view being displayed.
 @property(nonatomic, retain, readonly)
     CRWWebViewContentView* webViewContentView;
 // The native controller whose content is being displayed.
 @property(nonatomic, retain, readonly) id<CRWNativeContent> nativeController;
 // The currently displayed transient content view.
 @property(nonatomic, retain, readonly) CRWContentView* transientContentView;
+@property(nonatomic, assign) id<CRWWebControllerContainerViewDelegate>
+    delegate;  // weak
 
 // Designated initializer.  |proxy|'s content view will be updated as different
 // content is added to the container.
 - (instancetype)initWithDelegate:
         (id<CRWWebControllerContainerViewDelegate>)delegate
     NS_DESIGNATED_INITIALIZER;
 
 // CRWWebControllerContainerView should be initialized via
 // |-initWithContentViewProxy:|.
 - (instancetype)initWithCoder:(NSCoder*)decoder NS_UNAVAILABLE;
@@ skipping 28 matching lines @@
 
 // Removes |toolbar| as a subview.
 - (void)removeToolbar:(UIView*)toolbar;
 
 // Removes all toolbars added via |-addToolbar:|.
 - (void)removeAllToolbars;
 
 @end
 
 #endif  // IOS_WEB_WEB_STATE_UI_CRW_WEB_CONTROLLER_CONTAINER_VIEW_H_