jni_generator: Pass object parameters as JavaParamRef.

chrome/browser/android/precache/precache_launcher.cc

 // Copyright 2014 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 "chrome/browser/android/precache/precache_launcher.h"
 
 #include <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_weak_ref.h"
@@ skipping 62 matching lines @@
   precache_manager->CancelPrecaching();
 }
 
 void PrecacheLauncher::OnPrecacheCompleted(bool try_again_soon) {
   JNIEnv* env = AttachCurrentThread();
   Java_PrecacheLauncher_onPrecacheCompletedCallback(
       env, weak_java_precache_launcher_.get(env).obj(),
       try_again_soon ? JNI_TRUE : JNI_FALSE);
 }
 
-static jlong Init(JNIEnv* env, jobject obj) {
+static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   return reinterpret_cast<intptr_t>(new PrecacheLauncher(env, obj));
 }
 
 // Must be run on the UI thread.
-static jboolean ShouldRun(JNIEnv* env, jobject obj) {
+static jboolean ShouldRun(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   Profile* profile = GetProfile();
   PrecacheManager* precache_manager = GetPrecacheManager(profile);
   return precache_manager && (precache_manager->IsInExperimentGroup() ||
                               precache_manager->IsInControlGroup());
 }
 
 bool RegisterPrecacheLauncher(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }