Gracefully handle being signed out of a supervised profile.

chrome/browser/signin/mutable_profile_oauth2_token_service.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/signin/mutable_profile_oauth2_token_service.h"
 
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/webdata/web_data_service_factory.h"
 #include "components/signin/core/webdata/token_web_data.h"
 #include "components/webdata/common/web_data_service_base.h"
@@ skipping 231 matching lines @@
 #if defined(OS_IOS)
   // ProfileOauth2TokenService does not manage the refresh tokens on iOS - the
   // account info on iOS is only used to manage the authentication error state.
   // Simply add an account info entry with empty refresh token if none exists.
   if (refresh_tokens_.count(account_id) == 0) {
       refresh_tokens_[account_id].reset(
           new AccountInfo(this, account_id, std::string()));
   }
 #endif
 
-  DCHECK_GT(refresh_tokens_.count(account_id), 0u);
+  if (refresh_tokens_.count(account_id) == 0) {
+    // This could happen if the preferences have been corrupted (see
+    // http://crbug.com/321370). In a Debug build that would be a bug, but in a
+    // Release build we want to deal with it gracefully.
+    NOTREACHED();
+    return;
+  }
   refresh_tokens_[account_id]->SetLastAuthError(error);
 }
 
 std::vector<std::string> MutableProfileOAuth2TokenService::GetAccounts() {
   std::vector<std::string> account_ids;
   for (AccountInfoMap::const_iterator iter = refresh_tokens_.begin();
            iter != refresh_tokens_.end(); ++iter) {
     account_ids.push_back(iter->first);
   }
   return account_ids;
@@ skipping 91 matching lines @@
 #endif
 
   return GetPrimaryAccountId();
 }
 
 void MutableProfileOAuth2TokenService::RevokeCredentialsOnServer(
     const std::string& refresh_token) {
   // RevokeServerRefreshToken deletes itself when done.
   new RevokeServerRefreshToken(refresh_token, GetRequestContext());
 }