Mac Keychain store name should be based on branding.

components/os_crypt/keychain_password_mac.mm

Index: components/os_crypt/keychain_password_mac.mm
diff --git a/components/os_crypt/keychain_password_mac.mm b/components/os_crypt/keychain_password_mac.mm
index 2ce10cde4437d71f0822ed7a86cddc01bd2d8c39..1f60b9f0572ae9c61cf1d257c1457bb5b42838a4 100644
--- a/components/os_crypt/keychain_password_mac.mm
+++ b/components/os_crypt/keychain_password_mac.mm
@@ -51,7 +51,7 @@ std::string KeychainPassword::GetPassword() const {
   // These two strings ARE indeed user facing.  But they are used to access
   // the encryption keyword.  So as to not lose encrypted data when system
   // locale changes we DO NOT LOCALIZE.
-#if defined(OFFICIAL_BUILD)
+#if defined(GOOGLE_CHROME_BUILD)
   const std::string service_name = "Chrome Safe Storage";
   const std::string account_name = "Chrome";
 #else