Remove CRWSessionEntry.

ios/web/navigation/crw_session_entry.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/web/navigation/crw_session_entry.h"
-
-#include <stdint.h>
-
-#include <memory>
-
-#import "base/mac/scoped_nsobject.h"
-#include "base/strings/sys_string_conversions.h"
-#import "ios/web/navigation/navigation_item_impl.h"
-#import "ios/web/navigation/nscoder_util.h"
-#import "ios/web/public/navigation_item.h"
-#import "ios/web/public/web_state/page_display_state.h"
-#import "net/base/mac/url_conversions.h"
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-@interface CRWSessionEntry () {
-  // The NavigationItemImpl corresponding to this CRWSessionEntry.
-  // TODO(stuartmorgan): Move ownership to NavigationManagerImpl.
-  std::unique_ptr<web::NavigationItemImpl> _navigationItem;
-}
-
-@end
-
-@implementation CRWSessionEntry
-
-- (instancetype)initWithNavigationItem:
-    (std::unique_ptr<web::NavigationItem>)item {
-  self = [super init];
-  if (self) {
-    _navigationItem.reset(
-        static_cast<web::NavigationItemImpl*>(item.release()));
-  }
-  return self;
-}
-
-// TODO(ios): Shall we overwrite EqualTo:?
-
-- (instancetype)copyWithZone:(NSZone*)zone {
-  CRWSessionEntry* copy = [[[self class] alloc] init];
-  copy->_navigationItem.reset(
-      new web::NavigationItemImpl(*_navigationItem.get()));
-  return copy;
-}
-
-- (NSString*)description {
-#ifndef NDEBUG
-  return _navigationItem->GetDescription();
-#else
-  return [super description];
-#endif
-}
-
-- (web::NavigationItem*)navigationItem {
-  return _navigationItem.get();
-}
-
-- (web::NavigationItemImpl*)navigationItemImpl {
-  return _navigationItem.get();
-}
-
-@end