jni_generator: Pass object parameters as JavaParamRef.

chrome/browser/android/cookies/cookies_fetcher.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 "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/cookies/cookies_fetcher.h"
 #include "chrome/browser/profiles/profile_manager.h"
@@ skipping 143 matching lines @@
   net::CookieMonster* monster = store->GetCookieMonster();
   base::Callback<void(bool success)> cb;
 
   monster->SetCookieWithDetailsAsync(
       cookie.Source(), cookie.Name(), cookie.Value(), cookie.Domain(),
       cookie.Path(), cookie.ExpiryDate(), cookie.IsSecure(),
       cookie.IsHttpOnly(), cookie.IsFirstPartyOnly(), cookie.Priority(), cb);
 }
 
 // JNI functions
-static jlong Init(JNIEnv* env, jobject obj) {
+static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   return reinterpret_cast<intptr_t>(new CookiesFetcher(env, obj, 0));
 }
 
 // Register native methods
 bool RegisterCookiesFetcher(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }