ChromeOS cryptohome should be able to use gaia id as user identifier.

chromeos/cryptohome/cryptohome_parameters.h

Index: chromeos/cryptohome/cryptohome_parameters.h
diff --git a/chromeos/cryptohome/cryptohome_parameters.h b/chromeos/cryptohome/cryptohome_parameters.h
index 3738b56bce8870607b828197b32cfd6552119f30..1b2752dd49f2b951f29b38a4366fdc852e8ee3a3 100644
--- a/chromeos/cryptohome/cryptohome_parameters.h
+++ b/chromeos/cryptohome/cryptohome_parameters.h
@@ -13,6 +13,8 @@
 #include "base/memory/scoped_ptr.h"
 #include "chromeos/chromeos_export.h"
 
+class AccountId;
+
 namespace cryptohome {
 
 enum AuthKeyPrivileges {
@@ -25,12 +27,21 @@ enum AuthKeyPrivileges {
 };
 
 // Identification of the user calling cryptohome method.
-struct CHROMEOS_EXPORT Identification {
-  explicit Identification(const std::string& user_id);
+class CHROMEOS_EXPORT Identification {
+ public:
+  explicit Identification(const AccountId& account_id);
 
   bool operator==(const Identification& other) const;
 
-  std::string user_id;
+  // This method should be used for migration purpose only.
+  static Identification FromString(const std::string& id);
+
+  const std::string& id() const { return id_; }
+
+ private:
+  explicit Identification(const std::string&);
+
+  std::string id_;
 };

[xiyuan, 2016/02/17 23:14:26]

DISALLOW_COPY_AND_ASSIGN() ?

[Alexander Alekseev, 2016/02/18 13:45:14]

It is copied and used in PostTask in several places around the code.

 
 // Definition of the key (e.g. password) for the cryptohome.