Make GCMDriver::GetInstanceIDHandler protected, to avoid misuse

components/gcm_driver/instance_id/instance_id.h

Index: components/gcm_driver/instance_id/instance_id.h
diff --git a/components/gcm_driver/instance_id/instance_id.h b/components/gcm_driver/instance_id/instance_id.h
index 9adf0e5def2604150b45e9a3f99fdbe5614cc9ee..865f3bb0dce58cd4bc703e82c0d98efe724c5613 100644
--- a/components/gcm_driver/instance_id/instance_id.h
+++ b/components/gcm_driver/instance_id/instance_id.h
@@ -14,7 +14,7 @@
 #include "base/time/time.h"
 
 namespace gcm {
-class GCMDriver;
+class InstanceIDHandler;
 }  // namespace gcm
 
 namespace instance_id {
@@ -57,9 +57,9 @@ class InstanceID {
   // Creator.
   // |app_id|: identifies the application that uses the Instance ID.
   // |gcm_driver|: driver to access the GCM functionalities needed to support

[Peter Beverloo, 2016/03/11 16:10:19]

Please update this comment.

[johnme, 2016/03/11 17:53:23]

Done.

-  //               Instance ID.
+  //               Instance ID. Its InstanceIDHandler must outlive this class.
   static scoped_ptr<InstanceID> Create(const std::string& app_id,
-                                       gcm::GCMDriver* gcm_driver);
+                                       gcm::InstanceIDHandler* handler);
 
   virtual ~InstanceID();
 
@@ -106,11 +106,14 @@ class InstanceID {
   std::string app_id() const { return app_id_; }
 
  protected:
-  explicit InstanceID(const std::string& app_id);
+  InstanceID(const std::string& app_id, gcm::InstanceIDHandler* handler);
 
   void NotifyTokenRefresh(bool update_id);
 
+  gcm::InstanceIDHandler* handler() { return handler_; }

[Peter Beverloo, 2016/03/11 16:10:19]

Can this be const? (Like the method you're replacing.)

[johnme, 2016/03/11 17:53:22]

Done.

+
  private:
+  gcm::InstanceIDHandler* handler_;  // Not owned.

[Peter Beverloo, 2016/03/11 16:10:19]

Personally I would prefer documenting *why* it's safe to store it here. The fact
that it's not owned is implied by it not being a scoped_(ref)ptr.

[johnme, 2016/03/11 17:53:23]

Done: "
// Owned by GCMProfileServiceFactory, which is a dependency of
// InstanceIDProfileServiceFactory, which owns this."

ditto in instance_id_driver.h

   std::string app_id_;
   TokenRefreshCallback token_refresh_callback_;