[Sync] Fix namespaces for the sync_sessions component.

chrome/browser/sync/sync_sessions_metrics_android.cc

-// Copyright 2016 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/sync/sync_sessions_metrics_android.h"
-
-#include <string>
-
-#include "base/metrics/field_trial.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/profiles/profile_manager.h"
-#include "chrome/browser/sync/profile_sync_service_factory.h"
-#include "components/browser_sync/browser/profile_sync_service.h"
-#include "components/sync_sessions/sessions_sync_manager.h"
-#include "components/sync_sessions/sync_sessions_metrics.h"
-#include "jni/SyncSessionsMetrics_jni.h"
-
-// static
-bool SyncSessionsMetricsAndroid::Register(JNIEnv* env) {
-  return RegisterNativesImpl(env);
-}
-
-// static
-void RecordYoungestForeignTabAgeOnNTP(
-    JNIEnv* env,
-    const base::android::JavaParamRef<jclass>& jcaller) {
-  // Unlike other platforms, Android typically disables session invalidations to
-  // conserve battery. This means that the foreign tab data may be quite stale.
-  // This would drastically distort the metric we want to emit here, however the
-  // revisit experiement disables said optimization, allowing us to collect
-  // valid data but at the cost of a much smaller sample size.
-  const std::string group_name =
-      base::FieldTrialList::FindFullName("PageRevisitInstrumentation");
-  bool shouldInstrument = group_name == "Enabled";
-  if (shouldInstrument) {
-    Profile* profile = ProfileManager::GetActiveUserProfile();
-    if (profile) {
-      ProfileSyncService* sync =
-          ProfileSyncServiceFactory::GetForProfile(profile);
-      if (sync) {
-        browser_sync::SessionsSyncManager* sessions =
-            static_cast<browser_sync::SessionsSyncManager*>(
-                sync->GetSessionsSyncableService());
-        if (sessions) {
-          sync_sessions::SyncSessionsMetrics::RecordYoungestForeignTabAgeOnNTP(
-              sessions);
-        }
-      }
-    }
-  }
-}