This CL replaces user_manager::UserID with AccountId.

chromeos/login/auth/user_context.cc

Index: chromeos/login/auth/user_context.cc
diff --git a/chromeos/login/auth/user_context.cc b/chromeos/login/auth/user_context.cc
index 1f630c278ec127526483c132308a11605c36f18d..987b53790eb5937d117b2dea692aa72b796ac943 100644
--- a/chromeos/login/auth/user_context.cc
+++ b/chromeos/login/auth/user_context.cc
@@ -8,10 +8,10 @@
 namespace chromeos {
 
 UserContext::UserContext()
-    : is_using_oauth_(true),
+    : user_id_(EmptyAccountId()),

[achuithb, 2015/10/23 00:08:51]

in class member initialization, also remove initializers below

[Alexander Alekseev, 2015/10/23 09:11:24]

This is dangerous, as EmptyAccountId fits only default constructor.
This structure has many field members, and constructors must initialize
account_id_ specifically to match constructor context.

That is why we do not have default initialization in AccountId.
So let's force constructors to explicitly initialize this field.

+      is_using_oauth_(true),
       auth_flow_(AUTH_FLOW_OFFLINE),
-      user_type_(user_manager::USER_TYPE_REGULAR) {
-}
+      user_type_(user_manager::USER_TYPE_REGULAR) {}
 
 UserContext::UserContext(const UserContext& other)
     : user_id_(other.user_id_),
@@ -30,22 +30,24 @@ UserContext::UserContext(const UserContext& other)
       gaps_cookie_(other.gaps_cookie_) {
 }
 
-UserContext::UserContext(const std::string& user_id)
-    : user_id_(login::CanonicalizeUserID(user_id)),
+UserContext::UserContext(const AccountId& user_id)
+    : user_id_(user_id),
       is_using_oauth_(true),
       auth_flow_(AUTH_FLOW_OFFLINE),
       user_type_(user_manager::USER_TYPE_REGULAR) {
+  user_id_.SetUserEmail(login::CanonicalizeUserID(user_id.GetUserEmail()));
 }
 
 UserContext::UserContext(user_manager::UserType user_type,
                          const std::string& user_id)
-    : is_using_oauth_(true),
+    : user_id_(EmptyAccountId()),
+      is_using_oauth_(true),
       auth_flow_(AUTH_FLOW_OFFLINE),
       user_type_(user_type) {
   if (user_type_ == user_manager::USER_TYPE_REGULAR)
-    user_id_ = login::CanonicalizeUserID(user_id);
+    user_id_ = AccountId::FromUserEmail(login::CanonicalizeUserID(user_id));
   else
-    user_id_ = user_id;
+    user_id_ = AccountId::FromUserEmail(user_id);
 }
 
 UserContext::~UserContext() {
@@ -67,7 +69,7 @@ bool UserContext::operator!=(const UserContext& context) const {
   return !(*this == context);
 }
 
-const std::string& UserContext::GetUserID() const {
+const AccountId& UserContext::GetUserID() const {
   return user_id_;
 }
 
@@ -133,7 +135,7 @@ bool UserContext::HasCredentials() const {
 }
 
 void UserContext::SetUserID(const std::string& user_id) {
-  user_id_ = login::CanonicalizeUserID(user_id);
+  user_id_ = AccountId::FromUserEmail(login::CanonicalizeUserID(user_id));
 }
 
 void UserContext::SetGaiaID(const std::string& gaia_id) {