Clean-up coding style

extensions/common/features/json_feature_provider_source.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/json_feature_provider_source.h"
 
-#include <string>
-
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace extensions {
 
 JSONFeatureProviderSource::JSONFeatureProviderSource(const std::string& name)
     : name_(name) {
 }
 
@@ skipping 25 matching lines @@
        iter.Advance()) {
     if (dictionary_.GetWithoutPathExpansion(iter.key(), NULL))
       LOG(FATAL) << "Key " << iter.key() << " is defined in " << name_
                  << " JSON feature files more than once.";
   }
 
   // Merge.
   dictionary_.MergeDictionary(value_as_dict.get());
 }
 
-}  // namespace
+}  // namespace extensions