Notify about major session changes events.

ash/session_state_delegate_stub.cc

Index: ash/session_state_delegate_stub.cc
diff --git a/ash/session_state_delegate_stub.cc b/ash/session_state_delegate_stub.cc
index dcbd346dfd478123008ebb3f243995d8b1be8c96..473cf2c07601660d5673e3c7e731c0f80e5ac723 100644
--- a/ash/session_state_delegate_stub.cc
+++ b/ash/session_state_delegate_stub.cc
@@ -69,6 +69,12 @@ bool SessionStateDelegateStub::IsUserSessionBlocked() const  {
   return !IsActiveUserSessionStarted() || IsScreenLocked();
 }
 
+SessionStateDelegate::SessionState SessionStateDelegateStub::GetSessionState()
+    const {
+  // Assume that if session is not active we're at login.
+  return IsActiveUserSessionStarted() ? STATE_SESSION : STATE_LOGIN_PRIMARY;
+}
+
 const base::string16 SessionStateDelegateStub::GetUserDisplayName(
     MultiProfileIndex index) const {
   return base::UTF8ToUTF16("stub-user");