Moved serialization out of CRWSessionEntry.

ios/web/public/crw_navigation_manager_storage.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_PUBLIC_CRW_NAVIGATION_MANAGER_STORAGE_H_
 #define IOS_WEB_PUBLIC_CRW_NAVIGATION_MANAGER_STORAGE_H_
 
 #import <Foundation/Foundation.h>
 
 @class CRWSessionCertificatePolicyManager;
 
 // NSCoding-compliant class used to serialize NavigationManager's persisted
 // properties.
 // TODO(crbug.com/685388): Investigate using code from the sessions component.
 @interface CRWNavigationManagerStorage : NSObject<NSCoding>
 
 @property(nonatomic, copy) NSString* tabID;
 @property(nonatomic, copy) NSString* openerID;
 @property(nonatomic, getter=isOpenedByDOM) BOOL openedByDOM;
 @property(nonatomic, assign) NSInteger openerNavigationIndex;
 @property(nonatomic, copy) NSString* windowName;
 @property(nonatomic, assign) NSInteger currentNavigationIndex;
 @property(nonatomic, assign) NSInteger previousNavigationIndex;
 @property(nonatomic, assign) NSTimeInterval lastVisitedTimestamp;
-// TODO(crbug.com/454984): |entries| currently contains CRWSessionEntries.  Once
-// NavigationItemImpls are encoded/decoded using CRWNavigationItemSerializations
-// (analogous to the approach taken with NavigationManager), this will
-// become an array of CRWNavigationItemSerializations.
+// |entries| is an NSArray of CRWNavigationItemStorages.
 @property(nonatomic, copy) NSArray* entries;
 @property(nonatomic, retain)
     CRWSessionCertificatePolicyManager* sessionCertificatePolicyManager;
 
 @end
 
 #endif  // IOS_WEB_PUBLIC_CRW_NAVIGATION_MANAGER_STORAGE_H_