Fix refresh token is not available after Chrome restart on crash.

chrome/browser/chromeos/login/session/user_session_manager.cc

Index: chrome/browser/chromeos/login/session/user_session_manager.cc
diff --git a/chrome/browser/chromeos/login/session/user_session_manager.cc b/chrome/browser/chromeos/login/session/user_session_manager.cc
index abb9800fe02076957094ae59cd1ff309fa824b9d..dd2b4102c606c4243508222391d603a187440919 100644
--- a/chrome/browser/chromeos/login/session/user_session_manager.cc
+++ b/chrome/browser/chromeos/login/session/user_session_manager.cc
@@ -548,6 +548,12 @@ void UserSessionManager::RestoreAuthenticationSession(Profile* user_profile) {
 
   const user_manager::User* user =
       ProfileHelper::Get()->GetUserByProfile(user_profile);
+
+  const SigninManagerBase* signin_manager =
+      SigninManagerFactory::GetForProfile(user_profile);
+  if (!signin_manager || signin_manager->GetAuthenticatedAccountId().empty())
+    LOG(ERROR) << "No account is associated with sign-in manager on restore.";

[msarda, 2017/03/16 16:41:57]

Suggestion: Consider adding a UMA histogram for this to be able to monitor how
often this event occurs.

[khmel, 2017/03/16 17:06:36]

Nice point!

+
   DCHECK(user);
   if (!net::NetworkChangeNotifier::IsOffline()) {
     pending_signin_restore_sessions_.erase(user->GetAccountId().GetUserEmail());