Fix for scoring password autofill candidates:

components/password_manager/core/browser/password_form_manager.cc

Index: components/password_manager/core/browser/password_form_manager.cc
diff --git a/components/password_manager/core/browser/password_form_manager.cc b/components/password_manager/core/browser/password_form_manager.cc
index 70fc1e5c98335fdc5f76aa04738f650f59415d71..943bd240913b7272cda66c124f3c14663c7332c9 100644
--- a/components/password_manager/core/browser/password_form_manager.cc
+++ b/components/password_manager/core/browser/password_form_manager.cc
@@ -633,9 +633,10 @@ void PasswordFormManager::CheckForAccountCreationForm(
 int PasswordFormManager::ScoreResult(const PasswordForm& candidate) const {
   DCHECK_EQ(state_, MATCHING_PHASE);
   // For scoring of candidate login data:
-  // The most important element that should match is the origin, followed by
-  // the action, the password name, the submit button name, and finally the
-  // username input field name.
+  // The most important element that should match is the signon_realm followed
+  // by the origin the action, the password name, the submit button name, and
+  // finally the username input field name.
+  // Exact signon realm match gives an addition of 128 (1 << 7).
   // Exact origin match gives an addition of 64 (1 << 6) + # of matching url
   // dirs.
   // Partial match gives an addition of 32 (1 << 5) + # matching url dirs
@@ -645,7 +646,12 @@ int PasswordFormManager::ScoreResult(const PasswordForm& candidate) const {
   // If public suffix origin match was not used, it gives an addition of
   // 16 (1 << 4).
   int score = 0;
-  if (candidate.origin == observed_form_.origin) {
+  if (candidate.original_signon_realm.empty() ||
+      candidate.original_signon_realm == observed_form_.signon_realm) {

[Garrett Casto, 2014/04/17 21:12:39]

Actually, I think this should just be !candidate.IsPublicSuffixMatch(). This is
equivalent to the first statement. The second statement shouldn't matter, as
original_signon_realm should only be set if it doesn't match
observer_form_.signon_realm.

+    // If credentials come from different signon realm, then
+    // original_signon_realm will be non-empty string
+    score += (1 << 7);

[Garrett Casto, 2014/04/17 21:12:39]

This isn't completely consistent here, but I think that you should drop the
parenthesis.

+  } else if (candidate.origin == observed_form_.origin) {
     // This check is here for the most common case which
     // is we have a single match in the db for the given host,
     // so we don't generally need to walk the entire URL path (the else