Support getting and deleting token for Instance ID.

google_apis/gcm/engine/gcm_store_impl.h

Index: google_apis/gcm/engine/gcm_store_impl.h
diff --git a/google_apis/gcm/engine/gcm_store_impl.h b/google_apis/gcm/engine/gcm_store_impl.h
index 4815b2022bc1fa7022ce614a0eae45ff47cd3d25..8feebff048d52a51adfd2b9f81cb3a8559eb01f1 100644
--- a/google_apis/gcm/engine/gcm_store_impl.h
+++ b/google_apis/gcm/engine/gcm_store_impl.h
@@ -49,10 +49,10 @@ class GCM_EXPORT GCMStoreImpl : public GCMStore {
                             const UpdateCallback& callback) override;
 
   // Registration info.
-  void AddRegistration(const std::string& app_id,
-                       const linked_ptr<RegistrationInfo>& registration,
+  void AddRegistration(const std::string& serialized_key,
+                       const std::string& serialized_value,
                        const UpdateCallback& callback) override;
-  void RemoveRegistration(const std::string& app_id,
+  void RemoveRegistration(const std::string& serialized_key,
                           const UpdateCallback& callback) override;
 
   // Unacknowledged incoming message handling.