Add missing using statements for JNI types.

chrome/browser/android/metrics/variations_session.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/metrics/variations_session.h"
 
 #include "base/android/jni_string.h"
 #include "chrome/browser/browser_process.h"
 #include "components/variations/service/variations_service.h"
 #include "jni/VariationsSession_jni.h"
 
+using base::android::JavaParamRef;
+
 namespace {
 
 // Tracks whether VariationsService::OnAppEnterForeground() has been called
 // previously, in order to set the restrict mode param before the first call.
 bool g_on_app_enter_foreground_called = false;
 
 }  // namespace
 
 static void StartVariationsSession(
     JNIEnv* env,
@@ skipping 16 matching lines @@
 }
 
 namespace chrome {
 namespace android {
 
 // Register native methods
 bool RegisterVariationsSession(JNIEnv* env) { return RegisterNativesImpl(env); }
 
 }  // namespace android
 }  // namespace chrome