This CL replaces e-mail with AccountId on user selection screen.

components/signin/core/account_id/account_id.h

Index: components/signin/core/account_id/account_id.h
diff --git a/components/signin/core/account_id/account_id.h b/components/signin/core/account_id/account_id.h
index 73be4501db5b0ab107937acced10ee17d478a5e2..6dfe18fdca431be3e47a9fff8f3b9e5d243f901d 100644
--- a/components/signin/core/account_id/account_id.h
+++ b/components/signin/core/account_id/account_id.h
@@ -45,8 +45,11 @@ class AccountId {
   static AccountId FromUserEmailGaiaId(const std::string& user_email,
                                        const std::string& gaia_id);
 
-  // std::string Serialize() const;
-  // static AccountId Deserialize(const std::string& serialized);
+  // This is (for now) unstable and cannot be used to store serialized data to
+  // persistent storage. Only in-memory storage is safe.
+  std::string Serialize() const;
+  static bool Deserialize(const std::string& serialized,
+                          AccountId* out_account_id);

[stevenjb, 2015/11/11 20:39:23]

Even if these are unstable, please document that these input and output JSON
dictionaries.

[Alexander Alekseev, 2015/11/12 06:53:04]

Done.

 
  private:
   AccountId();