Pass method parameters as JavaParamRef in android_webview.

android_webview/native/aw_pdf_exporter.cc

 // Copyright 2013 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 "android_webview/native/aw_pdf_exporter.h"
 
 #include "android_webview/browser/aw_print_manager.h"
 #include "base/android/jni_android.h"
 #include "content/public/browser/browser_thread.h"
 #include "jni/AwPdfExporter_jni.h"
@@ skipping 15 matching lines @@
 AwPdfExporter::~AwPdfExporter() {
   JNIEnv* env = base::android::AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
   if (obj.is_null())
     return;
   // Clear the Java peer's weak pointer to |this| object.
   Java_AwPdfExporter_setNativeAwPdfExporter(env, obj.obj(), 0);
 }
 
 void AwPdfExporter::ExportToPdf(JNIEnv* env,
-                                jobject obj,
+                                const JavaParamRef<jobject>& obj,
                                 int fd,
-                                jobject cancel_signal) {
+                                const JavaParamRef<jobject>& cancel_signal) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   printing::PrintSettings print_settings;
   InitPdfSettings(env, obj, print_settings);
   AwPrintManager* print_manager =
       AwPrintManager::CreateForWebContents(
           web_contents_, print_settings, base::FileDescriptor(fd, false),
           base::Bind(&AwPdfExporter::DidExportPdf, base::Unretained(this)));
 
   if (!print_manager->PrintNow())
     DidExportPdf(fd, false);
@@ skipping 47 matching lines @@
   if (obj.is_null())
     return;
   Java_AwPdfExporter_didExportPdf(env, obj.obj(), success);
 }
 
 bool RegisterAwPdfExporter(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android_webview