jni_generator: Pass object parameters as JavaParamRef.

chrome/browser/android/compositor/scene_layer/tab_list_scene_layer.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 "chrome/browser/android/compositor/scene_layer/tab_list_scene_layer.h"
 
 #include "base/android/jni_android.h"
 #include "chrome/browser/android/compositor/layer/content_layer.h"
 #include "chrome/browser/android/compositor/layer/tab_layer.h"
 #include "chrome/browser/android/compositor/layer_title_cache.h"
@@ skipping 184 matching lines @@
     return layers_[write_index_++];
 
   scoped_refptr<TabLayer> layer = TabLayer::Create(
       incognito, resource_manager_, layer_title_cache_, tab_content_manager_);
   layers_.push_back(layer);
   own_tree_->AddChild(layer->layer());
   write_index_++;
   return layer;
 }
 
-static jlong Init(JNIEnv* env, jobject jobj) {
+static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& jobj) {
   // This will automatically bind to the Java object and pass ownership there.
   TabListSceneLayer* scene_layer = new TabListSceneLayer(env, jobj);
   return reinterpret_cast<intptr_t>(scene_layer);
 }
 
 bool RegisterTabListSceneLayer(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace chrome