jni_generator: Pass object parameters as JavaParamRef.

net/test/embedded_test_server/android/embedded_test_server_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 "net/test/embedded_test_server/android/embedded_test_server_android.h"
 
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ skipping 39 matching lines @@
     jstring jdirectory_path) {
   const base::FilePath directory(
       base::android::ConvertJavaStringToUTF8(env, jdirectory_path));
   test_server_.ServeFilesFromDirectory(directory);
 }
 
 void EmbeddedTestServerAndroid::Destroy(JNIEnv* env, jobject jobj) {
   delete this;
 }
 
-static void Init(JNIEnv* env, jobject jobj) {
+static void Init(JNIEnv* env, const JavaParamRef<jobject>& jobj) {
   TRACE_EVENT0("native", "EmbeddedTestServerAndroid::Init");
   new EmbeddedTestServerAndroid(env, jobj);
 }
 
 // static
 bool EmbeddedTestServerAndroid::RegisterEmbeddedTestServerAndroid(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace test_server
 }  // namespace net