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 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 200 matching lines @@
 
   // Removes the Instance ID data for a specific app from the persistent store.
   virtual void RemoveInstanceIDData(const std::string& app_id) = 0;
 
   // Retrieves the Instance ID data for a specific app from the persistent
   // store.
   virtual void GetInstanceIDData(const std::string& app_id,
                                  std::string* instance_id,
                                  std::string* extra_data) = 0;
 
+  // Returns whether this is the special category used for Instance IDs sending
+  // their |app_id| to GCM as a "subtype" (see security note at implementation).
+  virtual bool CategoryHasSubtype(const std::string& category) = 0;

[Peter Beverloo, 2016/07/22 12:17:03]

What's the benefit of keeping the ambiguously named "CategoryHasSubtype"
mentioning a "special category" if introducing the concept of a "product
subtype" would catch them all?

[johnme, 2016/07/26 17:11:55]

Fair. I've inlined this into GCMClientImpl::HandleIncomingMessage.

+
   // Gets and sets custom heartbeat interval for the MCS connection.
   // |scope| is used to identify the component that requests a custom interval
   // 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_