PasswordStore: Clean up expectations about rewriting vectors of forms

chrome/browser/password_manager/password_store_x.cc

Index: chrome/browser/password_manager/password_store_x.cc
diff --git a/chrome/browser/password_manager/password_store_x.cc b/chrome/browser/password_manager/password_store_x.cc
index 595770f599d5d222c47aca3eed0661fdd58341bf..eecb417b8c12b5f17276b994e9f37b7e05d14dda 100644
--- a/chrome/browser/password_manager/password_store_x.cc
+++ b/chrome/browser/password_manager/password_store_x.cc
@@ -145,13 +145,14 @@ ScopedVector<autofill::PasswordForm> PasswordStoreX::FillMatchingLogins(
     // The native backend may succeed and return no data even while locked, if
     // the query did not match anything stored. So we continue to allow fallback
     // until we perform a write operation, or until a read returns actual data.
-    if (matched_forms.size() > 0)
+    if (!matched_forms.empty())
       allow_fallback_ = false;
-  } else if (allow_default_store()) {
-    DCHECK(matched_forms.empty());
+    return matched_forms.Pass();
+  }
+  if (allow_default_store()) {

[engedy, 2015/03/09 13:33:18]

nit: -{}

[vabr (Chromium), 2015/03/09 17:44:15]

Done.

     return PasswordStoreDefault::FillMatchingLogins(form, prompt_policy);
   }
-  return matched_forms.Pass();
+  return ScopedVector<autofill::PasswordForm>();
 }
 
 void PasswordStoreX::GetAutofillableLoginsImpl(
@@ -195,6 +196,7 @@ void PasswordStoreX::GetBlacklistLoginsImpl(
 
 bool PasswordStoreX::FillAutofillableLogins(
     ScopedVector<autofill::PasswordForm>* forms) {
+  forms->clear();
   CheckMigration();
   if (use_native_backend() && backend_->GetAutofillableLogins(forms)) {
     // See GetLoginsImpl() for why we disallow fallback conditionally here.
@@ -209,6 +211,7 @@ bool PasswordStoreX::FillAutofillableLogins(
 
 bool PasswordStoreX::FillBlacklistLogins(
     ScopedVector<autofill::PasswordForm>* forms) {
+  forms->clear();
   CheckMigration();
   if (use_native_backend() && backend_->GetBlacklistLogins(forms)) {
     // See GetLoginsImpl() for why we disallow fallback conditionally here.
@@ -257,8 +260,12 @@ bool PasswordStoreX::allow_default_store() {
 ssize_t PasswordStoreX::MigrateLogins() {
   DCHECK(backend_.get());
   ScopedVector<autofill::PasswordForm> forms;
+  ScopedVector<autofill::PasswordForm> blacklist_forms;
   bool ok = PasswordStoreDefault::FillAutofillableLogins(&forms) &&
-      PasswordStoreDefault::FillBlacklistLogins(&forms);
+            PasswordStoreDefault::FillBlacklistLogins(&blacklist_forms);
+  forms.reserve(forms.size() + blacklist_forms.size());
+  forms.insert(forms.end(), blacklist_forms.begin(), blacklist_forms.end());
+  blacklist_forms.weak_clear();
   if (ok) {
     // We add all the passwords (and blacklist entries) to the native backend
     // before attempting to remove any from the login database, to make sure we