Add support for GCM subtypes to desktop Instance ID implementation

components/gcm_driver/gcm_client.h

 // 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.
 
 #ifndef COMPONENTS_GCM_DRIVER_GCM_CLIENT_H_
 #define COMPONENTS_GCM_DRIVER_GCM_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 80 matching lines @@
     CHANNEL_UNKNOWN
   };
 
   struct ChromeBuildInfo {
     ChromeBuildInfo();
     ~ChromeBuildInfo();
 
     ChromePlatform platform;
     ChromeChannel channel;
     std::string version;
+    std::string product_category_for_subtypes;
   };
 
   // Detailed information of the Send Error event.
   struct SendErrorDetails {
     SendErrorDetails();
     SendErrorDetails(const SendErrorDetails& other);
     ~SendErrorDetails();
 
     std::string message_id;
     MessageData additional_data;
@@ skipping 212 matching lines @@
   // to be set, and allows that component to later revoke the setting. It should
   // be unique.
   virtual void AddHeartbeatInterval(const std::string& scope,
                                     int interval_ms) = 0;
   virtual void RemoveHeartbeatInterval(const std::string& scope) = 0;
 };
 
 }  // namespace gcm
 
 #endif  // COMPONENTS_GCM_DRIVER_GCM_CLIENT_H_