ash: Use session_manager::SessionState

ash/common/session/session_state_observer.h

Index: ash/common/session/session_state_observer.h
diff --git a/ash/common/session/session_state_observer.h b/ash/common/session/session_state_observer.h
index cc323660e5b8bee0593b6c686307433042b8b6c7..83978e9de88475b543522541869db5db29623082 100644
--- a/ash/common/session/session_state_observer.h
+++ b/ash/common/session/session_state_observer.h
@@ -6,7 +6,7 @@
 #define ASH_COMMON_SESSION_SESSION_STATE_OBSERVER_H_
 
 #include "ash/ash_export.h"
-#include "ash/common/session/session_state_delegate.h"
+#include "ash/common/session/session_types.h"
 #include "base/macros.h"
 
 class AccountId;
@@ -22,7 +22,7 @@ class ASH_EXPORT SessionStateObserver {
   virtual void UserAddedToSession(const AccountId& account_id) {}
 
   // Called when session state is changed.
-  virtual void SessionStateChanged(SessionStateDelegate::SessionState state) {}
+  virtual void SessionStateChanged(SessionState state) {}
 
  protected:
   virtual ~SessionStateObserver() {}