Add missing using statements for JNI types.

chrome/browser/android/metrics/launch_metrics.cc

 // Copyright (c) 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/launch_metrics.h"
 
 #include "base/android/jni_string.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/shortcut_info.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/engagement/site_engagement_service.h"
 #include "chrome/browser/prefs/pref_metrics_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/rappor/rappor_utils.h"
 #include "content/public/browser/web_contents.h"
 #include "jni/LaunchMetrics_jni.h"
 #include "url/gurl.h"
 
+using base::android::JavaParamRef;
+
 namespace metrics {
 
 enum HomeScreenLaunch {
   HOME_SCREEN_LAUNCH_STANDALONE = 0,
   HOME_SCREEN_LAUNCH_SHORTCUT = 1,
   HOME_SCREEN_LAUNCH_COUNT = 2
 };
 
 bool RegisterLaunchMetrics(JNIEnv* env) {
   return RegisterNativesImpl(env);
@@ skipping 63 matching lines @@
     jboolean homepage_is_ntp,
     const JavaParamRef<jstring>& jhomepage_url) {
   GURL homepage_url(base::android::ConvertJavaStringToUTF8(env, jhomepage_url));
   PrefMetricsService::RecordHomePageLaunchMetrics(
       show_home_button,
       homepage_is_ntp,
       homepage_url);
 }
 
 };  // namespace metrics