[Sync] Move //components/sync_driver to //components/sync/driver.

components/sync_driver/device_count_metrics_provider.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 "components/sync_driver/device_count_metrics_provider.h"
-
-#include <algorithm>
-
-#include "base/metrics/sparse_histogram.h"
-#include "components/sync_driver/device_info_tracker.h"
-
-namespace sync_driver {
-
-DeviceCountMetricsProvider::DeviceCountMetricsProvider(
-    const ProvideTrackersCallback& provide_trackers)
-    : provide_trackers_(provide_trackers) {}
-
-DeviceCountMetricsProvider::~DeviceCountMetricsProvider() {}
-
-int DeviceCountMetricsProvider::MaxActiveDeviceCount() const {
-  std::vector<const sync_driver::DeviceInfoTracker*> trackers;
-  provide_trackers_.Run(&trackers);
-  int max = 0;
-  for (auto* tracker : trackers) {
-    max = std::max(max, tracker->CountActiveDevices());
-  }
-  return max;
-}
-
-void DeviceCountMetricsProvider::ProvideGeneralMetrics(
-    metrics::ChromeUserMetricsExtension* uma_proto) {
-  UMA_HISTOGRAM_SPARSE_SLOWLY("Sync.DeviceCount",
-                              std::min(MaxActiveDeviceCount(), 100));
-}
-
-}  // namespace sync_driver