Remove usage of Tab's |url| property from TabModel.

ios/web/navigation/navigation_manager_impl.h

 // 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.
 
 #ifndef IOS_WEB_NAVIGATION_NAVIGATION_MANAGER_IMPL_H_
 #define IOS_WEB_NAVIGATION_NAVIGATION_MANAGER_IMPL_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 87 matching lines @@
   // type and user agent override option, making it the pending item. If pending
   // item is the same as the current item, this does nothing. |referrer| may be
   // nil if there isn't one. The item starts out as pending, and will be lost
   // unless |-commitPendingItem| is called.
   void AddPendingItem(const GURL& url,
                       const web::Referrer& referrer,
                       ui::PageTransition navigation_type,
                       NavigationInitiationType initiation_type,
                       UserAgentOverrideOption user_agent_override_option);
 
+  // Commits the pending item, if any.
+  void CommitPendingItem();
+
   // NavigationManager:
   BrowserState* GetBrowserState() const override;
   WebState* GetWebState() const override;
   NavigationItem* GetVisibleItem() const override;
   NavigationItem* GetLastCommittedItem() const override;
   NavigationItem* GetPendingItem() const override;
   NavigationItem* GetTransientItem() const override;
   void DiscardNonCommittedItems() override;
   void LoadURLWithParams(const NavigationManager::WebLoadParams&) override;
   void AddTransientURLRewriter(
@@ skipping 58 matching lines @@
   // List of transient url rewriters added by |AddTransientURLRewriter()|.
   std::unique_ptr<std::vector<BrowserURLRewriter::URLRewriter>>
       transient_url_rewriters_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationManagerImpl);
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_NAVIGATION_NAVIGATION_MANAGER_IMPL_H_