Add support for GCM subtypes to desktop Instance ID implementation

components/gcm_driver/instance_id/instance_id_driver.h

 // Copyright 2015 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_INSTANCE_ID_INSTANCE_ID_DRIVER_H_
 #define COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_DRIVER_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 12 matching lines @@
 // implementation.
 class InstanceIDDriver {
  public:
   // Returns whether InstanceID is enabled.
   static bool IsInstanceIDEnabled();
 
   explicit InstanceIDDriver(gcm::GCMDriver* gcm_driver);
   virtual ~InstanceIDDriver();
 
   // Returns the InstanceID that provides the Instance ID service for the given
-  // application. The lifetime of InstanceID will be managed by this class.
+  // application. The lifetime of the InstanceID will be managed by this class.
   InstanceID* GetInstanceID(const std::string& app_id);
 
+  // Like |GetInstanceID|, except that for historical reasons, Chrome Apps and
+  // Extensions send the |app_id| to GCM as a "category" instead of a "subtype".
+  // Not recommended for new code, since this does not (and cannot) support
+  // Android, and switching between this and |GetInstanceID| is not supported (a
+  // given |app_id| must either always use |GetInstanceID| or always use
+  // |GetInstanceIDForExtensions|, even across Chrome versions).
+  InstanceID* GetInstanceIDForExtensions(const std::string& app_id);
+
   // Removes the InstanceID when it is not longer needed, i.e. the app is being
   // uninstalled.
   void RemoveInstanceID(const std::string& app_id);
 
   // Returns true if the InstanceID for the given application has been created.
   // This is currently only used for testing purpose.
   bool ExistsInstanceID(const std::string& app_id) const;
 
  private:
+  InstanceID* GetInstanceID(const std::string& app_id, bool use_subtype);
+
   // Owned by GCMProfileServiceFactory, which is a dependency of
   // InstanceIDProfileServiceFactory, which owns this.
   gcm::GCMDriver* gcm_driver_;
 
   std::map<std::string, std::unique_ptr<InstanceID>> instance_id_map_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDDriver);
 };
 
 }  // namespace instance_id
 
 #endif  // COMPONENTS_GCM_DRIVER_INSTANCE_ID_INSTANCE_ID_DRIVER_H_