jni_generator: Pass object parameters as JavaParamRef.

chrome/browser/android/compositor/scene_layer/reader_mode_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/reader_mode_scene_layer.h"
 
 #include "base/android/jni_android.h"
 #include "chrome/browser/android/compositor/layer/reader_mode_layer.h"
 #include "content/public/browser/android/content_view_core.h"
 #include "jni/ReaderModeSceneLayer_jni.h"
@@ skipping 46 matching lines @@
 
   reader_mode_layer_->SetProperties(
       panel_background_resource_id, panel_text_resource_id,
       content_view_core,
       panel_y, panel_width, panel_margin_top, panel_height,
       distilled_y, distilled_height,
       x,
       panel_text_opacity, header_background_color);
 }
 
-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.
   ReaderModeSceneLayer* tree_provider =
       new ReaderModeSceneLayer(env, jobj);
   return reinterpret_cast<intptr_t>(tree_provider);
 }
 
 bool RegisterReaderModeSceneLayer(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace chrome