Clean up source_site_instance usage in Navigator::RequestOpenURL.

content/browser/security_exploit_browsertest.cc

Index: content/browser/security_exploit_browsertest.cc
diff --git a/content/browser/security_exploit_browsertest.cc b/content/browser/security_exploit_browsertest.cc
index 6a167b9c329a6f9b295495940b94bfdb8a00757d..9932011f5373b0d1051500198362a43b869702a3 100644
--- a/content/browser/security_exploit_browsertest.cc
+++ b/content/browser/security_exploit_browsertest.cc
@@ -91,8 +91,8 @@ RenderViewHostImpl* PrepareToDuplicateHosts(Shell* shell,
   WebContentsImpl* wc = static_cast<WebContentsImpl*>(shell->web_contents());
   wc->GetFrameTree()->root()->navigator()->RequestOpenURL(
       wc->GetFrameTree()->root()->current_frame_host(), extension_url, false,
-      nullptr, std::string(), nullptr, Referrer(),
-      WindowOpenDisposition::CURRENT_TAB, false, true);
+      nullptr, std::string(), Referrer(), WindowOpenDisposition::CURRENT_TAB,
+      false, true);
 
   // Since the navigation above requires a cross-process swap, there will be a
   // speculative/pending RenderFrameHost. Ensure it exists and is in a different