Rename UserInfo method GetEmail to GetDisplayEmail.

ash/common/test/test_session_state_delegate.cc

Index: ash/common/test/test_session_state_delegate.cc
diff --git a/ash/common/test/test_session_state_delegate.cc b/ash/common/test/test_session_state_delegate.cc
index 84a89e23626bddea589181bc5a8b1f3605380bcd..28b60f3ce53f666974d539b3bbbdb557fce8fef4 100644
--- a/ash/common/test/test_session_state_delegate.cc
+++ b/ash/common/test/test_session_state_delegate.cc
@@ -54,7 +54,7 @@ class MockUserInfo : public user_manager::UserInfo {
     return base::UTF8ToUTF16("Über Über Über Über");
   }
 
-  std::string GetEmail() const override { return display_email_; }
+  std::string GetDisplayEmail() const override { return display_email_; }
 
   const AccountId& GetAccountId() const override { return account_id_; }