Add missing using statements for JNI types.

chrome/browser/android/webapps/webapp_registry.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/webapps/webapp_registry.h"
 
 #include <jni.h>
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "base/callback.h"
 #include "chrome/browser/android/browsing_data/url_filter_bridge.h"
 #include "chrome/browser/io_thread.h"
 #include "content/public/browser/browser_thread.h"
 #include "jni/WebappRegistry_jni.h"
 
+using base::android::JavaParamRef;
+
 void WebappRegistry::UnregisterWebappsForUrls(
     const base::Callback<bool(const GURL&)>& url_filter,
     const base::Closure& callback) {
   JNIEnv* env = base::android::AttachCurrentThread();
   // TODO(msramek): Consider implementing a wrapper class that will call and
   // destroy this closure from Java, eliminating the need for
   // OnWebappsUnregistered() and OnClearedWebappHistory() callbacks.
   uintptr_t callback_pointer = reinterpret_cast<uintptr_t>(
       new base::Closure(callback));
 
@@ skipping 34 matching lines @@
                             jlong jcallback) {
   base::Closure* callback = reinterpret_cast<base::Closure*>(jcallback);
   callback->Run();
   delete callback;
 }
 
 // static
 bool WebappRegistry::RegisterWebappRegistry(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }