Add missing using statements for JNI types.

chrome/browser/android/download/download_controller.cc

 // Copyright 2016 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/download/download_controller.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/android/context_utils.h"
@@ skipping 14 matching lines @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/common/referrer.h"
 #include "jni/DownloadController_jni.h"
 #include "net/base/filename_util.h"
 #include "ui/android/view_android.h"
 #include "ui/android/window_android.h"
 #include "ui/base/page_transition_types.h"
 
 using base::android::ConvertUTF8ToJavaString;
+using base::android::JavaParamRef;
 using base::android::ScopedJavaLocalRef;
 using content::BrowserContext;
 using content::BrowserThread;
 using content::ContextMenuParams;
 using content::DownloadItem;
 using content::DownloadManager;
 using content::WebContents;
 
 namespace {
 // Guards download_controller_
@@ skipping 386 matching lines @@
   if (!item)
     return;
   if (accept) {
     item->ValidateDangerousDownload();
   } else {
     DownloadController::RecordDownloadCancelReason(
         DownloadController::CANCEL_REASON_DANGEROUS_DOWNLOAD_INFOBAR_DISMISSED);
     item->Remove();
   }
 }