(Set)IsOverridingUserAgent should be called on VisibleItem

ios/web/web_state/ui/crw_web_controller.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/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 2344 matching lines @@
   // The page should be closed if it was initiated by the DOM and there has been
   // no user interaction with the page since the web view was created, or if
   // the page has no navigation items, as occurs when an App Store link is
   // opened from another application.
   BOOL rendererInitiatedWithoutInteraction =
       self.sessionController.openedByDOM && !_userInteractedWithWebController;
   BOOL noNavigationItems = !(self.navigationManagerImpl->GetItemCount());
   return rendererInitiatedWithoutInteraction || noNavigationItems;
 }
 
 - (BOOL)useDesktopUserAgent {

[kkhorimoto, 2017/02/22 01:08:40]

This property is only used once in |-webViewWithConfiguration:|.  Let's just
remove the property and inline the call to the NavigationManager function here.

[liaoyuke, 2017/02/22 01:37:43]

Done.

-  web::NavigationItem* item = [self currentNavItem];
-  return item && item->IsOverridingUserAgent();
+  return [self navigationManagerImpl]->GetUseDesktopUserAgent();
 }
 
 - (web::MojoFacade*)mojoFacade {
   if (!_mojoFacade) {
     service_manager::mojom::InterfaceProvider* interfaceProvider =
         _webStateImpl->GetMojoInterfaceRegistry();
     _mojoFacade.reset(new web::MojoFacade(interfaceProvider, self));
   }
   return _mojoFacade.get();
 }
@@ skipping 2940 matching lines @@
 - (void)simulateLoadRequestWithURL:(const GURL&)URL {
   _lastRegisteredRequestURL = URL;
   _loadPhase = web::LOAD_REQUESTED;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end