jni_generator: Pass object parameters as JavaParamRef.

components/dom_distiller/content/browser/distillable_page_utils_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 "components/dom_distiller/content/browser/distillable_page_utils_android.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "components/dom_distiller/content/browser/distillable_page_utils.h"
 #include "content/public/browser/web_contents.h"
 #include "jni/DistillablePageUtils_jni.h"
 
 using base::android::ScopedJavaGlobalRef;
 
 namespace dom_distiller {
 namespace android {
 namespace {
 void OnIsPageDistillableResult(
     scoped_ptr<ScopedJavaGlobalRef<jobject>> callback_holder,
     bool isDistillable) {
   Java_DistillablePageUtils_callOnIsPageDistillableResult(
       base::android::AttachCurrentThread(), callback_holder->obj(),
       isDistillable);
 }
 }  // namespace
 
 static void IsPageDistillable(JNIEnv* env,
-                              jclass jcaller,
-                              jobject webContents,
+                              const JavaParamRef<jclass>& jcaller,
+                              const JavaParamRef<jobject>& webContents,
                               jboolean is_mobile_optimized,
-                              jobject callback) {
+                              const JavaParamRef<jobject>& callback) {
   content::WebContents* web_contents(
       content::WebContents::FromJavaWebContents(webContents));
   scoped_ptr<ScopedJavaGlobalRef<jobject>> callback_holder(
       new ScopedJavaGlobalRef<jobject>());
   callback_holder->Reset(env, callback);
 
   if (!web_contents) {
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(OnIsPageDistillableResult,
                               base::Passed(&callback_holder), false));
     return;
   }
   IsDistillablePage(
       web_contents, is_mobile_optimized,
       base::Bind(OnIsPageDistillableResult, base::Passed(&callback_holder)));
 }
 
 bool RegisterDistillablePageUtils(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }
 }