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

extensions/browser/guest_view/web_view/web_view_guest.cc

Index: extensions/browser/guest_view/web_view/web_view_guest.cc
diff --git a/extensions/browser/guest_view/web_view/web_view_guest.cc b/extensions/browser/guest_view/web_view/web_view_guest.cc
index 36418980eadde3a8fa1d9fd78e76eafe7215b33b..218de7485e1a954126a0917624ff287fb4878c7a 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.cc
+++ b/extensions/browser/guest_view/web_view/web_view_guest.cc
@@ -1122,8 +1122,16 @@ content::WebContents* WebViewGuest::OpenURLFromTab(
     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,