Add support for GCM subtypes to desktop Instance ID implementation

components/gcm_driver/gcm_desktop_utils.h

Index: components/gcm_driver/gcm_desktop_utils.h
diff --git a/components/gcm_driver/gcm_desktop_utils.h b/components/gcm_driver/gcm_desktop_utils.h
index bd8ce48ca3fcdd17ef137a1fa4a78cb221cb5c69..258f5f837d21573b65cafe6601da535c66738eca 100644
--- a/components/gcm_driver/gcm_desktop_utils.h
+++ b/components/gcm_driver/gcm_desktop_utils.h
@@ -31,6 +31,7 @@ std::unique_ptr<GCMDriver> CreateGCMDriverDesktop(
     const base::FilePath& store_path,
     const scoped_refptr<net::URLRequestContextGetter>& request_context,
     version_info::Channel channel,
+    const std::string& category_for_subtypes,
     const scoped_refptr<base::SequencedTaskRunner>& ui_task_runner,
     const scoped_refptr<base::SequencedTaskRunner>& io_task_runner,
     const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner);