Pass JavaRef to Java methods in android_webview.

android_webview/native/aw_contents_background_thread_client.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 "android_webview/native/aw_contents_background_thread_client.h"
 
 #include "jni/AwContentsBackgroundThreadClient_jni.h"
 
+using base::android::JavaRef;
+
 namespace android_webview {
 
 // static
 base::android::ScopedJavaLocalRef<jobject>
 AwContentsBackgroundThreadClient::shouldInterceptRequest(
     JNIEnv* env,
-    jobject obj,
-    jstring url,
+    const JavaRef<jobject>& obj,
+    const JavaRef<jstring>& url,
     jboolean isMainFrame,
     jboolean hasUserGesture,
-    jstring method,
-    jobjectArray requestHeaderNames,
-    jobjectArray requestHeaderValues) {
+    const JavaRef<jstring>& method,
+    const JavaRef<jobjectArray>& requestHeaderNames,
+    const JavaRef<jobjectArray>& requestHeaderValues) {
   return Java_AwContentsBackgroundThreadClient_shouldInterceptRequestFromNative(
       env, obj, url, isMainFrame, hasUserGesture, method, requestHeaderNames,
       requestHeaderValues);
 }
 
 }  // namespace android_webview