Move the offline URL trimming to GetFormattedURL.

ios/web/public/test/test_navigation_manager.mm

Index: ios/web/public/test/test_navigation_manager.mm
diff --git a/ios/web/public/test/test_navigation_manager.mm b/ios/web/public/test/test_navigation_manager.mm
index 398d9677690edddb5e6252025f9762a9ed954a6b..6fea4adb9c9f3c01c81d92c59b0b7aea57f593fa 100644
--- a/ios/web/public/test/test_navigation_manager.mm
+++ b/ios/web/public/test/test_navigation_manager.mm
@@ -21,8 +21,11 @@ WebState* TestNavigationManager::GetWebState() const {
 }
 
 NavigationItem* TestNavigationManager::GetVisibleItem() const {
-  NOTREACHED();
-  return nullptr;
+  return visible_item_;
+}
+
+void TestNavigationManager::SetVisibleItem(NavigationItem* item) {
+  visible_item_ = item;
 }
 
 NavigationItem* TestNavigationManager::GetLastCommittedItem() const {