Set user agent type of transient item the same as pending item.

ios/web/public/test/web_test_with_web_state.h

Index: ios/web/public/test/web_test_with_web_state.h
diff --git a/ios/web/public/test/web_test_with_web_state.h b/ios/web/public/test/web_test_with_web_state.h
index b167056f398810c4538c4f91c8b2ff65a5f34798..bf9f29f3cb15b8bc3433865f2aa5eb43bbeb453a 100644
--- a/ios/web/public/test/web_test_with_web_state.h
+++ b/ios/web/public/test/web_test_with_web_state.h
@@ -8,6 +8,7 @@
 #import "base/ios/block_types.h"
 #include "base/message_loop/message_loop.h"
 #include "ios/web/public/test/web_test.h"
+#include "ui/base/page_transition_types.h"
 #include "url/gurl.h"
 
 namespace web {
@@ -25,6 +26,9 @@ class WebTestWithWebState : public WebTest,
   void SetUp() override;
   void TearDown() override;
 
+  // Adds a pending item to the NavigationManager associated with the WebState.
+  void AddPendingItem(const GURL& url, ui::PageTransition transition);
+
   // Loads the specified HTML content with URL into the WebState.
   void LoadHtml(NSString* html, const GURL& url);
   // Loads the specified HTML content into the WebState, using test url name.