Stop using the Keychain for passwords finally and clean up the Chrome entries there.

chrome/browser/password_manager/password_store_proxy_mac.h

Index: chrome/browser/password_manager/password_store_proxy_mac.h
diff --git a/chrome/browser/password_manager/password_store_proxy_mac.h b/chrome/browser/password_manager/password_store_proxy_mac.h
index ec9838684e78722dafe9f6caa9991900d31b33ca..2e4e42781862ade428a05f0452682e54b1652550 100644
--- a/chrome/browser/password_manager/password_store_proxy_mac.h
+++ b/chrome/browser/password_manager/password_store_proxy_mac.h
@@ -23,7 +23,6 @@ namespace password_manager {
 class LoginDatabase;
 }
 
-class PasswordStoreMac;
 class SimplePasswordStoreMac;
 
 // The class is a proxy for either PasswordStoreMac or SimplePasswordStoreMac.
@@ -48,8 +47,8 @@ class PasswordStoreProxyMac : public password_manager::PasswordStore {
     return login_metadata_db_.get();
   }
 
-  scoped_refptr<PasswordStoreMac> password_store_mac() {
-    return password_store_mac_;
+  crypto::AppleKeychain* keychain() {
+    return keychain_.get();
   }
 #endif
 
@@ -102,7 +101,6 @@ class PasswordStoreProxyMac : public password_manager::PasswordStore {
   std::vector<std::unique_ptr<password_manager::InteractionsStats>>
   GetSiteStatsImpl(const GURL& origin_domain) override;
 
-  scoped_refptr<PasswordStoreMac> password_store_mac_;
   scoped_refptr<SimplePasswordStoreMac> password_store_simple_;
 
   // The login metadata SQL database. If opening the DB on |thread_| fails,
@@ -110,6 +108,9 @@ class PasswordStoreProxyMac : public password_manager::PasswordStore {
   // The ownership may be transferred to |password_store_simple_|.
   std::unique_ptr<password_manager::LoginDatabase> login_metadata_db_;
 
+  // Keychain wrapper.
+  const std::unique_ptr<crypto::AppleKeychain> keychain_;
+
   // Thread that the synchronous methods are run on.
   std::unique_ptr<base::Thread> thread_;