Add GetOriginalRequestURL() to NavigationItem interface.

ios/web/navigation/navigation_item_impl.mm

Index: ios/web/navigation/navigation_item_impl.mm
diff --git a/ios/web/navigation/navigation_item_impl.mm b/ios/web/navigation/navigation_item_impl.mm
index 5fccafb555dc60fb703ab4210638416353ca6705..bc774c158aefefeb8cbebefc1b0efa83416d4cc6 100644
--- a/ios/web/navigation/navigation_item_impl.mm
+++ b/ios/web/navigation/navigation_item_impl.mm
@@ -53,6 +53,7 @@ static int GetUniqueIDInConstructor() {
 
 NavigationItemImpl::NavigationItemImpl(const NavigationItemImpl& item)
     : unique_id_(item.unique_id_),
+      original_request_url_(item.original_request_url_),
       url_(item.url_),
       referrer_(item.referrer_),
       virtual_url_(item.virtual_url_),
@@ -89,6 +90,14 @@ static int GetUniqueIDInConstructor() {
   return unique_id_;
 }
 
+void NavigationItemImpl::SetOriginalRequestURL(const GURL& url) {
+  original_request_url_ = url;
+}
+
+const GURL& NavigationItemImpl::GetOriginalRequestURL() const {
+  return original_request_url_;
+}
+
 void NavigationItemImpl::SetURL(const GURL& url) {
   url_ = url;
   cached_display_title_.clear();