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

ios/web/interstitials/web_interstitial_impl.mm

Index: ios/web/interstitials/web_interstitial_impl.mm
diff --git a/ios/web/interstitials/web_interstitial_impl.mm b/ios/web/interstitials/web_interstitial_impl.mm
index 1a9febb41a5510d446a02e7e28c507fae7d87804..3dec1ba07211155017f7abd335c76cfd2cdea2af 100644
--- a/ios/web/interstitials/web_interstitial_impl.mm
+++ b/ios/web/interstitials/web_interstitial_impl.mm
@@ -6,7 +6,6 @@
 
 #include "base/logging.h"
 #include "ios/web/interstitials/web_interstitial_facade_delegate.h"
-#import "ios/web/navigation/crw_session_controller.h"
 #import "ios/web/navigation/navigation_manager_impl.h"
 #import "ios/web/public/interstitials/web_interstitial_delegate.h"
 #import "ios/web/public/navigation_manager.h"
@@ -60,12 +59,9 @@
   GetWebStateImpl()->ShowWebInterstitial(this);
 
   if (new_navigation_) {
-    // TODO(stuartmorgan): Plumb transient entry handling through
-    // NavigationManager, and remove the NavigationManagerImpl and
-    // SessionController usage here.
-    CRWSessionController* sessionController =
-        navigation_manager_->GetSessionController();
-    [sessionController addTransientItemWithURL:url_];
+    // TODO(crbug.com/706578): Plumb transient entry handling through
+    // NavigationManager, and remove the NavigationManagerImpl usage here.
+    navigation_manager_->AddTransientItem(url_);
 
     // Give delegates a chance to set some states on the navigation item.
     GetDelegate()->OverrideItem(navigation_manager_->GetTransientItem());