Resolve conflict in chrome://flags and field trial config.

chrome/common/variations/variations_util.cc

 // Copyright 2014 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/common/variations/variations_util.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
@@ skipping 74 matching lines @@
       for (size_t j = 0; j < group.params_size; ++j) {
         const FieldTrialGroupParams& param = group.params[j];
         params[param.key] = param.value;
       }
       variations::AssociateVariationParams(group.study, group.group_name,
                                            params);
     }
     base::FieldTrial* trial =
         base::FieldTrialList::CreateFieldTrial(group.study, group.group_name);
 
+    if (!trial) {
+      DLOG(WARNING) << "Field trial config study skipped: " << group.study
+                    << "." << group.group_name
+                    << " (it is overridden from chrome://flags)";
+      continue;
+    }
+
     for (size_t j = 0; j < group.enable_features_size; ++j) {
       feature_list->RegisterFieldTrialOverride(
           group.enable_features[j], base::FeatureList::OVERRIDE_ENABLE_FEATURE,
           trial);
     }
     for (size_t j = 0; j < group.disable_features_size; ++j) {
       feature_list->RegisterFieldTrialOverride(
           group.disable_features[j],
           base::FeatureList::OVERRIDE_DISABLE_FEATURE, trial);
     }
   }
 }
 
 void AssociateDefaultFieldTrialConfig(base::FeatureList* feature_list) {
   AssociateParamsFromFieldTrialConfig(kFieldTrialConfig, feature_list);
 }
 
 }  // namespace chrome_variations