Add test case to see if HTTP auth interstitials work nicely with other interstitials

chrome/browser/ui/login/login_prompt.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/login/login_prompt.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 491 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   WebContents* parent_contents = handler->GetWebContentsForLogin();
   if (!parent_contents || handler->WasAuthHandled()) {
     // The request may have been cancelled, or it may be for a renderer
     // not hosted by a tab (e.g. an extension). Cancel just in case
     // (cancelling twice is a no-op).
     handler->CancelAuth();
     return;
   }
 
+  // For main frame navigations, show a blank interstitial if this is a cross
+  // origin request or if there is an existing interstitial.
   if (is_main_frame &&
-      parent_contents->GetVisibleURL().GetOrigin() != request_url.GetOrigin()) {
+      (parent_contents->GetInterstitialPage() ||

[nasko, 2014/07/17 14:08:44]

Is it correct that we hit this only after proceeding through the first
interstitial?

[meacer, 2014/07/17 22:08:18]

I can't think of any other state where an interstitial would already be shown.

+       parent_contents->GetVisibleURL().GetOrigin() != request_url.GetOrigin())
+      ) {
     // Show a blank interstitial for main-frame, cross origin requests
     // so that the correct URL is shown in the omnibox.
     base::Closure callback = base::Bind(&ShowLoginPrompt,
                                         request_url,
                                         make_scoped_refptr(auth_info),
                                         make_scoped_refptr(handler));
-    // This is owned by the interstitial it creates.
+
+    // This is owned by the interstitial it creates. The new interstitial will
+    // replace existing interstitial, if any.

[nasko, 2014/07/17 14:08:44]

I don't recall the ownership semantics of this. Would we leak the old
interstitial if we replace it with this one?

[meacer, 2014/07/17 22:08:18]

Interstitials clean up themselves on navigation. Since the login interstitial
creates a new navigation, the old one is cleaned up.

     new LoginInterstitialDelegate(parent_contents,
                                   request_url,
                                   callback);
   } else {
     ShowLoginPrompt(request_url,
                     auth_info,
                     handler);
   }
 }
 
 // ----------------------------------------------------------------------------
 // Public API
 
 LoginHandler* CreateLoginPrompt(net::AuthChallengeInfo* auth_info,
                                 net::URLRequest* request) {
   bool is_main_frame = (request->load_flags() & net::LOAD_MAIN_FRAME) != 0;
   LoginHandler* handler = LoginHandler::Create(auth_info, request);
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&LoginDialogCallback, request->url(),
                  make_scoped_refptr(auth_info), make_scoped_refptr(handler),
                  is_main_frame));
   return handler;
 }