Add CHECK on session start for profile construction

components/session_manager/core/session_manager.h

Index: components/session_manager/core/session_manager.h
diff --git a/components/session_manager/core/session_manager.h b/components/session_manager/core/session_manager.h
index 27dc34b719d3135d470a2dd1d062d2cb906201a5..666cc73a8f86754da5a318bc5bf26bbc46cc7639 100644
--- a/components/session_manager/core/session_manager.h
+++ b/components/session_manager/core/session_manager.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_SESSION_MANAGER_CORE_SESSION_MANAGER_H_
 #define COMPONENTS_SESSION_MANAGER_CORE_SESSION_MANAGER_H_
 
+#include <string>
 #include <vector>
 
 #include "base/macros.h"
@@ -49,6 +50,9 @@ class SESSION_EXPORT SessionManager {
   // before the session has been started.
   virtual void SessionStarted();
 
+  // Returns true if the session for the given user was started.
+  bool HasSessionForAccountId(const AccountId& user_account_id) const;
+
   // Convenience wrapps of session state.
   bool IsInSecondaryLoginScreen() const;
   bool IsScreenLocked() const;