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

chrome/browser/chromeos/login/screens/chrome_user_selection_screen.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/login/screens/chrome_user_selection_screen.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 59 matching lines @@
   CheckForPublicSessionLocalePolicyChange(broker);
 }
 
 void ChromeUserSelectionScreen::OnDeviceLocalAccountsChanged() {
   // Nothing to do here. When the list of device-local accounts changes, the
   // entire UI is reloaded.
 }
 
 void ChromeUserSelectionScreen::CheckForPublicSessionDisplayNameChange(
     policy::DeviceLocalAccountPolicyBroker* broker) {
-  const std::string& user_id = broker->user_id();
+  const AccountId& account_id(GetAccountIdOfKnownUser(broker->user_id()));

[dzhioev (left Google), 2015/11/13 23:17:37]

nit: such syntax seems weird to me.
Why not const AccountId& account_id = ...; ?

[Alexander Alekseev, 2015/11/14 00:27:42]

Done.

   const std::string& display_name = broker->GetDisplayName();
-  if (display_name == public_session_display_names_[user_id])
+  if (display_name == public_session_display_names_[account_id])
     return;
 
-  public_session_display_names_[user_id] = display_name;
+  public_session_display_names_[account_id] = display_name;
 
   if (!handler_initialized_)
     return;
 
   if (!display_name.empty()) {
     // If a new display name was set by policy, notify the UI about it.
-    view_->SetPublicSessionDisplayName(user_id, display_name);
+    view_->SetPublicSessionDisplayName(account_id, display_name);
     return;
   }
 
   // When no display name is set by policy, the |User|, owned by |UserManager|,
   // decides what display name to use. However, the order in which |UserManager|
   // and |this| are informed of the display name change is undefined. Post a
   // task that will update the UI after the UserManager is guaranteed to have
   // been informed of the change.
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&ChromeUserSelectionScreen::SetPublicSessionDisplayName,
-                 weak_factory_.GetWeakPtr(),
-                 user_id));
+                 weak_factory_.GetWeakPtr(), account_id));
 }
 
 void ChromeUserSelectionScreen::CheckForPublicSessionLocalePolicyChange(
     policy::DeviceLocalAccountPolicyBroker* broker) {
-  const std::string& user_id = broker->user_id();
+  const AccountId account_id(GetAccountIdOfKnownUser(broker->user_id()));

[dzhioev (left Google), 2015/11/13 23:17:37]

Why account_id is not a reference here?

[Alexander Alekseev, 2015/11/14 00:27:42]

Because it is generated and temporary inside GetKnownAccountIdOfKnownUser().

[dzhioev (left Google), 2015/11/14 01:21:15]

It is perfectly legal to bind const reference to a temporary object (and  you
are already doing that in line 80).
http://herbsutter.com/2008/01/01/gotw-88-a-candidate-for-the-most-important-c...

[Alexander Alekseev, 2015/11/14 07:10:33]

Done.

   const policy::PolicyMap::Entry* entry =
       broker->core()->store()->policy_map().Get(policy::key::kSessionLocales);
 
   // Parse the list of recommended locales set by policy.
   std::vector<std::string> new_recommended_locales;
   base::ListValue const* list = NULL;
   if (entry &&
       entry->level == policy::POLICY_LEVEL_RECOMMENDED &&
       entry->value &&
       entry->value->GetAsList(&list)) {
     for (base::ListValue::const_iterator it = list->begin(); it != list->end();
          ++it) {
       std::string locale;
       if (!(*it)->GetAsString(&locale)) {
         NOTREACHED();
         new_recommended_locales.clear();
         break;
       }
       new_recommended_locales.push_back(locale);
     }
   }
 
   std::vector<std::string>& recommended_locales =
-      public_session_recommended_locales_[user_id];
+      public_session_recommended_locales_[account_id];
 
   if (new_recommended_locales != recommended_locales)
-    SetPublicSessionLocales(user_id, new_recommended_locales);
+    SetPublicSessionLocales(account_id, new_recommended_locales);
 
   if (new_recommended_locales.empty())
-    public_session_recommended_locales_.erase(user_id);
+    public_session_recommended_locales_.erase(account_id);
   else
     recommended_locales = new_recommended_locales;
 }
 
 void ChromeUserSelectionScreen::SetPublicSessionDisplayName(
-    const std::string& user_id) {
-  const user_manager::User* user = user_manager::UserManager::Get()->FindUser(
-      AccountId::FromUserEmail(user_id));
+    const AccountId& account_id) {
+  const user_manager::User* user =
+      user_manager::UserManager::Get()->FindUser(account_id);
   if (!user || user->GetType() != user_manager::USER_TYPE_PUBLIC_ACCOUNT)
     return;
 
-  view_->SetPublicSessionDisplayName(user_id,
+  view_->SetPublicSessionDisplayName(account_id,
                                      base::UTF16ToUTF8(user->GetDisplayName()));
 }
 
 void ChromeUserSelectionScreen::SetPublicSessionLocales(
-    const std::string& user_id,
+    const AccountId& account_id,
     const std::vector<std::string>& recommended_locales) {
   if (!handler_initialized_)
     return;
 
   // Construct the list of available locales. This list consists of the
   // recommended locales, followed by all others.
   scoped_ptr<base::ListValue> available_locales =
       GetUILanguageList(&recommended_locales, std::string());
 
   // Set the initially selected locale to the first recommended locale that is
   // actually available or the current UI locale if none of them are available.
   const std::string default_locale = FindMostRelevantLocale(
       recommended_locales,
       *available_locales.get(),
       g_browser_process->GetApplicationLocale());
 
   // Set a flag to indicate whether the list of recommended locales contains at
   // least two entries. This is used to decide whether the public session pod
   // expands to its basic form (for zero or one recommended locales) or the
   // advanced form (two or more recommended locales).
   const bool two_or_more_recommended_locales = recommended_locales.size() >= 2;
 
   // Notify the UI.
-  view_->SetPublicSessionLocales(user_id, available_locales.Pass(),
+  view_->SetPublicSessionLocales(account_id, available_locales.Pass(),
                                  default_locale,
                                  two_or_more_recommended_locales);
 }
 
 }  // namespace chromeos