Add missing using statements for JNI types.

components/policy/core/browser/android/android_combined_policy_provider.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/policy/core/browser/android/android_combined_policy_provider.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "components/policy/core/browser/android/policy_converter.h"
 #include "jni/CombinedPolicyProvider_jni.h"
 
 using base::android::AttachCurrentThread;
+using base::android::JavaParamRef;
 
 namespace {
 
 bool g_wait_for_policies = false;
 
 }  // namespace
 
 namespace policy {
 namespace android {
 
@@ skipping 36 matching lines @@
     PolicyDomain domain) const {
   return initialized_;
 }
 
 bool AndroidCombinedPolicyProvider::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace policy