Add test for showing confirmation dialog for unsecure signin

chrome/browser/resources/gaia_auth/main.js

Index: chrome/browser/resources/gaia_auth/main.js
diff --git a/chrome/browser/resources/gaia_auth/main.js b/chrome/browser/resources/gaia_auth/main.js
index 1c61a2448150e9d110e5aa9ae4682331e695b599..ba48c65dc9049f2dc8cb453d754480286497b3f8 100644
--- a/chrome/browser/resources/gaia_auth/main.js
+++ b/chrome/browser/resources/gaia_auth/main.js
@@ -428,6 +428,11 @@ Authenticator.prototype = {
         this.maybeCompleteSAMLLogin_();
       }
     } else if (msg.method == 'confirmLogin' && this.isInternalMessage_(e)) {
+      // In the desktop mode, Chrome needs to wait for extra info such as
+      // session index from the background JS.
+      if (this.desktopMode_)
+        return;
+
       if (this.attemptToken_ == msg.attemptToken)
         this.onConfirmLogin_();
       else