[NTP::Push] Add the classes for sending a breaking news subscription request

components/ntp_snippets/breaking_news/subscription_request_params.h

+// Copyright 2017 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_BREAKING_NEWS_SUBSCRIPTION_REQUEST_PARAMS_H_
+#define COMPONENTS_NTP_SNIPPETS_BREAKING_NEWS_SUBSCRIPTION_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 {
+
+// Contains all parameters for subscribing for breaking news push messages.
+struct SubscriptionRequestParams {
+  SubscriptionRequestParams();
+  SubscriptionRequestParams(const SubscriptionRequestParams&);
+  ~SubscriptionRequestParams();
+
+  // GCM subscription token obtained from GCM driver (instanceID::getToken())
+  std::string token;
+
+  // TODO(mamir): Additional fields to be added: country, language.
+};
+
+// Callbacks for JSON parsing to allow injecting platform-dependent code.
+using SuccessCallback =
+    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_BREAKING_NEWS_SUBSCRIPTION_REQUEST_PARAMS_H_