Clean-up coding style

extensions/common/features/complex_feature.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 "extensions/common/features/complex_feature.h"
 
+#include <set>
+
 namespace extensions {
 
 ComplexFeature::ComplexFeature(scoped_ptr<FeatureList> features) {
   DCHECK_GT(features->size(), 0UL);
   features_.swap(*features);
   no_parent_ = features_[0]->no_parent();
 
 #if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
   // Verify GetContexts, IsInternal, & IsBlockedInServiceWorker are consistent
   // across all features.
@@ skipping 114 matching lines @@
                                                    Context context) const {
   if (result == IS_AVAILABLE)
     return std::string();
 
   // TODO(justinlin): Form some kind of combined availabilities/messages from
   // SimpleFeatures.
   return features_[0]->GetAvailabilityMessage(result, type, url, context);
 }
 
 }  // namespace extensions