Password manager: improve the check for login failure

chrome/test/data/password/password_form.html

Index: chrome/test/data/password/password_form.html
diff --git a/chrome/test/data/password/password_form.html b/chrome/test/data/password/password_form.html
index 6f194b30f7842248839d1bf2e2f2f15a31528a8e..c271025394c2269def57c422837066bbfda2579e 100644
--- a/chrome/test/data/password/password_form.html
+++ b/chrome/test/data/password/password_form.html
@@ -40,5 +40,17 @@ needs to access them by their offsets in the array of the form children.
   <input type="submit">
 </form>
 
+<form method="POST" action="done_and_unrelated_form.html" id="to_unrelated">
+  <input type="text" id="username_unrelated" name="username_unrelated">
+  <input type="password" id="password_unrelated" name="password_unrelated">
+  <input type="submit" id="submit_unrelated" name="submit_unrelated">
+</form>
+
+<form method="POST" action="failed.html" id="to_failed">
+  <input type="text" id="username_failed" name="username_failed">
+  <input type="password" id="password_failed" name="password_failed">
+  <input type="submit" id="submit_failed" name="submit_failed">
+</form>
+
 </body>
 </html>