Add missing using statements for JNI types.

chrome/browser/android/metrics/uma_session_stats.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/uma_session_stats.h"
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/installer/util/google_update_settings.h"
 #include "components/metrics/metrics_pref_names.h"
 #include "components/metrics/metrics_service.h"
 #include "components/metrics_services_manager/metrics_services_manager.h"
 #include "components/prefs/pref_service.h"
 #include "components/variations/metrics_util.h"
 #include "components/variations/variations_associated_data.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/user_metrics.h"
 #include "jni/UmaSessionStats_jni.h"
 
 using base::android::ConvertJavaStringToUTF8;
+using base::android::JavaParamRef;
 using base::UserMetricsAction;
 
 namespace {
 UmaSessionStats* g_uma_session_stats = NULL;
 }  // namespace
 
 UmaSessionStats::UmaSessionStats()
     : active_session_count_(0) {
 }
 
@@ skipping 172 matching lines @@
   // We should have only one UmaSessionStats instance.
   DCHECK(!g_uma_session_stats);
   g_uma_session_stats = new UmaSessionStats();
   return reinterpret_cast<intptr_t>(g_uma_session_stats);
 }
 
 // Register native methods
 bool RegisterUmaSessionStats(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }