Add more debugging CHECKS to diagnose an Android renderer crash.

components/variations/service/variations_service.cc

 // Copyright (c) 2012 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 "components/variations/service/variations_service.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <utility>
 
@@ skipping 282 matching lines @@
   DCHECK(resource_request_allowed_notifier_.get());
 
   resource_request_allowed_notifier_->Init(this);
 }
 
 VariationsService::~VariationsService() {
 }
 
 bool VariationsService::CreateTrialsFromSeed(base::FeatureList* feature_list) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  CHECK(!create_trials_from_seed_called_);
 
   create_trials_from_seed_called_ = true;
 
   variations::VariationsSeed seed;
   if (!LoadSeed(&seed))
     return false;
 
   const int64_t last_fetch_time_internal =
       local_state_->GetInt64(prefs::kVariationsLastFetchTime);
   const base::Time last_fetch_time =
@@ skipping 545 matching lines @@
   std::string stored_country;
 
   if (list_value->GetSize() == 2) {
     list_value->GetString(1, &stored_country);
   }
 
   return stored_country;
 }
 
 }  // namespace variations