Add missing using statements for JNI types.

chrome/browser/supervised_user/child_accounts/child_account_service_android.cc

 // Copyright 2014 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/supervised_user/child_accounts/child_account_service_android.h"
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/supervised_user/child_accounts/child_account_service.h"
 #include "jni/ChildAccountService_jni.h"
 
+using base::android::JavaParamRef;
+
 jboolean IsChildAccountDetectionEnabled(JNIEnv* env,
                                         const JavaParamRef<jclass>& jcaller) {
   return ChildAccountService::IsChildAccountDetectionEnabled();
 }
 
 jboolean IsChildAccount(JNIEnv* env, const JavaParamRef<jclass>& jcaller) {
   ProfileManager* profile_manager = g_browser_process->profile_manager();
   return profile_manager->GetLastUsedProfile()->IsChild();
 }
 
 bool RegisterChildAccountService(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }