Add SessionStateObserver with ActiveUserChanged()

chrome/browser/ui/ash/session_state_delegate_chromeos.cc

Index: chrome/browser/ui/ash/session_state_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/session_state_delegate_chromeos.cc b/chrome/browser/ui/ash/session_state_delegate_chromeos.cc
index c9bb73e8c67ec9560ebd93a0779b9b8e9c3740f5..2f88649902dff2f9d6377fe659eeba0a53709743 100644
--- a/chrome/browser/ui/ash/session_state_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/session_state_delegate_chromeos.cc
@@ -6,11 +6,13 @@
 
 #include "base/logging.h"
 #include "chrome/browser/chromeos/login/screen_locker.h"
+#include "chrome/browser/chromeos/login/user.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 
 SessionStateDelegate::SessionStateDelegate() {
+  chromeos::UserManager::Get()->AddSessionStateObserver(this);
 }
 
 SessionStateDelegate::~SessionStateDelegate() {
@@ -86,3 +88,20 @@ void SessionStateDelegate::GetLoggedInUsers(
 void SessionStateDelegate::SwitchActiveUser(const std::string& email) {
   chromeos::UserManager::Get()->SwitchActiveUser(email);
 }
+
+void SessionStateDelegate::AddSessionStateObserver(
+    ash::SessionStateObserver* observer) {
+  session_state_observer_list_.AddObserver(observer);
+}
+
+void SessionStateDelegate::RemoveSessionStateObserver(
+    ash::SessionStateObserver* observer) {
+  session_state_observer_list_.RemoveObserver(observer);
+}
+
+void SessionStateDelegate::ActiveUserChanged(
+    const chromeos::User* active_user) {
+  FOR_EACH_OBSERVER(ash::SessionStateObserver,
+                    session_state_observer_list_,
+                    ActiveUserChanged(active_user->email()));
+}