Allow Signin page to open other chrome:// URLs if login content in <webview>

extensions/browser/guest_view/web_view/web_view_guest.cc

 // Copyright 2014 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 "extensions/browser/guest_view/web_view/web_view_guest.h"
 
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/browser_context.h"
@@ skipping 1104 matching lines @@
     new_window_info.changed = new_window_info.url != info.url;
     it->second = new_window_info;
     return nullptr;
   }
   if (params.disposition == CURRENT_TAB) {
     // This can happen for cross-site redirects.
     LoadURLWithParams(params.url, params.referrer, params.transition, source);
     return source;
   }
 
-  CreateNewGuestWebViewWindow(params);
-  return nullptr;
+  // Chrome Apps expect a newwindow event in response to Ctrl+Click.
+  if (in_extension()) {
+    CreateNewGuestWebViewWindow(params);
+    return nullptr;
+  }
+
+  if (!owner_web_contents()->GetDelegate())
+    return nullptr;
+  return owner_web_contents()->GetDelegate()->OpenURLFromTab(
+      owner_web_contents(), params);
 }
 
 void WebViewGuest::WebContentsCreated(WebContents* source_contents,
                                       int opener_render_frame_id,
                                       const base::string16& frame_name,
                                       const GURL& target_url,
                                       content::WebContents* new_contents) {
   auto guest = WebViewGuest::FromWebContents(new_contents);
   CHECK(guest);
   guest->SetOpener(this);
@@ skipping 78 matching lines @@
       WebViewGuest::From(owner_web_contents()->GetRenderProcessHost()->GetID(),
                          new_window_instance_id);
   if (!guest)
     return;
 
   if (!allow)
     guest->Destroy();
 }
 
 }  // namespace extensions