This CL replaces e-mail with AccountId in easy signin code.

chrome/browser/chromeos/login/screens/user_selection_screen.h

Index: chrome/browser/chromeos/login/screens/user_selection_screen.h
diff --git a/chrome/browser/chromeos/login/screens/user_selection_screen.h b/chrome/browser/chromeos/login/screens/user_selection_screen.h
index 70faa8be9038738488619f23412849fbe30d0c3c..2ec86fb076863fbf7c89270cb985a347a9ecc974 100644
--- a/chrome/browser/chromeos/login/screens/user_selection_screen.h
+++ b/chrome/browser/chromeos/login/screens/user_selection_screen.h
@@ -64,20 +64,20 @@ class UserSelectionScreen
   // proximity_auth::ScreenlockBridge::LockHandler implementation:
   void ShowBannerMessage(const base::string16& message) override;
   void ShowUserPodCustomIcon(
-      const std::string& user_email,
+      const AccountId& account_id,
       const proximity_auth::ScreenlockBridge::UserPodCustomIconOptions& icon)
       override;
-  void HideUserPodCustomIcon(const std::string& user_email) override;
+  void HideUserPodCustomIcon(const AccountId& account_id) override;
 
   void EnableInput() override;
-  void SetAuthType(const std::string& user_email,
+  void SetAuthType(const AccountId& account_id,
                    AuthType auth_type,
                    const base::string16& auth_value) override;
-  AuthType GetAuthType(const std::string& user_email) const override;
+  AuthType GetAuthType(const AccountId& account_id) const override;
   ScreenType GetScreenType() const override;
 
-  void Unlock(const std::string& user_email) override;
-  void AttemptEasySignin(const std::string& user_email,
+  void Unlock(const AccountId& account_id) override;
+  void AttemptEasySignin(const AccountId& account_id,
                          const std::string& secret,
                          const std::string& key_label) override;