Clean-up coding style

extensions/common/features/permission_feature.h

Index: extensions/common/features/permission_feature.h
diff --git a/extensions/common/features/permission_feature.h b/extensions/common/features/permission_feature.h
index 0a74ff02ca1164aa387fa91ae40464660c9864f4..5916fdd11e33f00b1dac0a4d79a7278ae81dcb6d 100644
--- a/extensions/common/features/permission_feature.h
+++ b/extensions/common/features/permission_feature.h
@@ -5,6 +5,8 @@
 #ifndef EXTENSIONS_COMMON_FEATURES_PERMISSION_FEATURE_H_
 #define EXTENSIONS_COMMON_FEATURES_PERMISSION_FEATURE_H_
 
+#include <string>
+
 #include "extensions/common/features/simple_feature.h"
 
 namespace extensions {
@@ -23,6 +25,6 @@ class PermissionFeature : public SimpleFeature {
   virtual std::string Parse(const base::DictionaryValue* value) OVERRIDE;
 };
 
-}  // extensions
+}  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_FEATURES_PERMISSION_FEATURE_H_