Remove friend classes from PasswordStore.

chrome/browser/password_manager/password_store_mac.cc

Index: chrome/browser/password_manager/password_store_mac.cc
diff --git a/chrome/browser/password_manager/password_store_mac.cc b/chrome/browser/password_manager/password_store_mac.cc
index 99aeff07b09f1e1eb67c17a2c3ea2d1c23b3fbd0..9cf6bd6107dc1ff48810bc19cd28bbdd4861b1cf 100644
--- a/chrome/browser/password_manager/password_store_mac.cc
+++ b/chrome/browser/password_manager/password_store_mac.cc
@@ -874,6 +874,7 @@ void PasswordStoreMac::ReportMetricsImpl() {
 
 PasswordStoreChangeList PasswordStoreMac::AddLoginImpl(
     const PasswordForm& form) {
+  DCHECK(thread_->message_loop() == base::MessageLoop::current());
   PasswordStoreChangeList changes;
   if (AddToKeychainIfNecessary(form)) {
     if (login_metadata_db_->AddLogin(form)) {
@@ -885,6 +886,7 @@ PasswordStoreChangeList PasswordStoreMac::AddLoginImpl(
 
 PasswordStoreChangeList PasswordStoreMac::UpdateLoginImpl(
     const PasswordForm& form) {
+  DCHECK(thread_->message_loop() == base::MessageLoop::current());
   PasswordStoreChangeList changes;
   int update_count = 0;
   if (!login_metadata_db_->UpdateLogin(form, &update_count))
@@ -916,6 +918,7 @@ PasswordStoreChangeList PasswordStoreMac::UpdateLoginImpl(
 
 PasswordStoreChangeList PasswordStoreMac::RemoveLoginImpl(
     const PasswordForm& form) {
+  DCHECK(thread_->message_loop() == base::MessageLoop::current());
   PasswordStoreChangeList changes;
   if (login_metadata_db_->RemoveLogin(form)) {
     // See if we own a Keychain item associated with this item. We can do an