Convert WindowOpenDisposition to an enum class.

ios/web/navigation/navigation_manager_impl.mm

 // Copyright 2013 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.
 
 #include "ios/web/navigation/navigation_manager_impl.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 150 matching lines @@
   }
 }
 
 CRWSessionController* NavigationManagerImpl::GetSessionController() {
   return session_controller_;
 }
 
 void NavigationManagerImpl::LoadURL(const GURL& url,
                                     const web::Referrer& referrer,
                                     ui::PageTransition type) {
-  WebState::OpenURLParams params(url, referrer, CURRENT_TAB, type, NO);
+  WebState::OpenURLParams params(url, referrer,
+                                 WindowOpenDisposition::CURRENT_TAB, type, NO);
   delegate_->GetWebState()->OpenURL(params);
 }
 
 NavigationItem* NavigationManagerImpl::GetLastUserItem() const {
   CRWSessionEntry* entry = [session_controller_ lastUserEntry];
   return [entry navigationItem];
 }
 
 NavigationItem* NavigationManagerImpl::GetPreviousItem() const {
   CRWSessionEntry* entry = [session_controller_ previousEntry];
@@ skipping 121 matching lines @@
   }
 }
 
 void NavigationManagerImpl::Reload(bool check_for_reposts) {
   // Navigation manager may be empty if the only pending entry failed to load
   // with SSL error and the user has decided not to proceed.
   NavigationItem* item = GetVisibleItem();
   GURL url = item ? item->GetURL() : GURL(url::kAboutBlankURL);
   web::Referrer referrer = item ? item->GetReferrer() : web::Referrer();
 
-  WebState::OpenURLParams params(url, referrer, CURRENT_TAB,
+  WebState::OpenURLParams params(url, referrer,
+                                 WindowOpenDisposition::CURRENT_TAB,
                                  ui::PAGE_TRANSITION_RELOAD, NO);
   delegate_->GetWebState()->OpenURL(params);
 }
 
 std::unique_ptr<std::vector<BrowserURLRewriter::URLRewriter>>
 NavigationManagerImpl::GetTransientURLRewriters() {
   return std::move(transient_url_rewriters_);
 }
 
 void NavigationManagerImpl::RemoveTransientURLRewriters() {
   transient_url_rewriters_.reset();
 }
 
 void NavigationManagerImpl::CopyState(
     NavigationManagerImpl* navigation_manager) {
   SetSessionController([navigation_manager->GetSessionController() copy]);
 }
 
 }  // namespace web