[Remote suggestions] Clean up variation params in the fetcher.

components/ntp_snippets/remote/request_params.h

 // Copyright 2016 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.
 
 #ifndef COMPONENTS_NTP_SNIPPETS_REMOTE_REQUEST_PARAMS_H_
 #define COMPONENTS_NTP_SNIPPETS_REMOTE_REQUEST_PARAMS_H_
 
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "base/optional.h"
 #include "base/values.h"
 #include "components/ntp_snippets/category.h"
 
 namespace ntp_snippets {
 
-// Enumeration listing all possible variants of dealing with personalization.
-enum class Personalization { kPersonal, kNonPersonal, kBoth };
-
 // Contains all parameters for fetching remote suggestions.
 struct RequestParams {
   RequestParams();
   RequestParams(const RequestParams&);
   ~RequestParams();
 
   // BCP 47 language code specifying the user's UI language.
   std::string language_code;
 
   // A set of suggestion IDs that should not be returned again.
@@ skipping 16 matching lines @@
     base::Callback<void(std::unique_ptr<base::Value> result)>;
 using ErrorCallback = base::Callback<void(const std::string& error)>;
 using ParseJSONCallback =
     base::Callback<void(const std::string& raw_json_string,
                         const SuccessCallback& success_callback,
                         const ErrorCallback& error_callback)>;
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_REMOTE_REQUEST_PARAMS_H_