jni_generator: Pass object parameters as JavaParamRef.

components/signin/core/browser/child_account_info_fetcher_android.cc

 // 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.
 
 #include "components/signin/core/browser/child_account_info_fetcher_android.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "components/signin/core/browser/account_fetcher_service.h"
 #include "jni/ChildAccountInfoFetcher_jni.h"
@@ skipping 15 matching lines @@
     bool is_child_account) {
   service->SetIsChildAccount(account_id, is_child_account);
 }
 
 // static
 bool ChildAccountInfoFetcherAndroid::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 void SetIsChildAccount(JNIEnv* env,
-                       jclass caller,
+                       const JavaParamRef<jclass>& caller,
                        jlong native_service,
-                       jstring j_account_id,
+                       const JavaParamRef<jstring>& j_account_id,
                        jboolean is_child_account) {
   AccountFetcherService* service =
       reinterpret_cast<AccountFetcherService*>(native_service);
   ChildAccountInfoFetcherAndroid::SetIsChildAccount(
       service, base::android::ConvertJavaStringToUTF8(env, j_account_id),
       is_child_account);
 }