(Set)IsOverridingUserAgent should be called on VisibleItem

ios/web/public/navigation_manager.h

Index: ios/web/public/navigation_manager.h
diff --git a/ios/web/public/navigation_manager.h b/ios/web/public/navigation_manager.h
index bec6c696e9d91976aa8beacb7be49e8835d33c52..f3e106dcba6f44cfdc9a75fd19ffc1dd53c25696 100644
--- a/ios/web/public/navigation_manager.h
+++ b/ios/web/public/navigation_manager.h
@@ -148,12 +148,6 @@ class NavigationManager {
   // reload the page. In nearly all cases pass in true.  If a transient item is
   // showing, initiates a new navigation to its URL.
   virtual void Reload(bool check_for_repost) = 0;
-
-  // Forces the pending item to be loaded using desktop user agent. Note that
-  // the pending item may or may not already exist.
-  // TODO(crbug.com/692303): Remove this when overriding the user agent doesn't
-  // create a new NavigationItem.
-  virtual void OverrideDesktopUserAgentForNextPendingItem() = 0;
 };
 
 }  // namespace web