[Sync] Create UserEventService.

components/sync/user_events/user_event_service.h

Index: components/sync/user_events/user_event_service.h
diff --git a/components/sync/user_events/user_event_service.h b/components/sync/user_events/user_event_service.h
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index 0000000000000000000000000000000000000000..f460d6c358bf5e30f71e5459aadd8a1e6e07f8db
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+++ b/components/sync/user_events/user_event_service.h
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+// Copyright 2017 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.
+
+#ifndef COMPONENTS_SYNC_USER_EVENTS_USER_EVENT_SERVICE_H_
+#define COMPONENTS_SYNC_USER_EVENTS_USER_EVENT_SERVICE_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "components/keyed_service/core/keyed_service.h"
+
+namespace sync_pb {
+class UserEventSpecifics;
+}  // namespace sync_pb
+
+namespace syncer {
+
+class ModelTypeSyncBridge;
+class SyncService;
+class UserEventSyncBridge;
+
+class UserEventService : public KeyedService {
+ public:
+  UserEventService(SyncService* sync_service,
+                   std::unique_ptr<UserEventSyncBridge> bridge);
+
+  ~UserEventService() override;
+
+  // KeyedService implementation
+  void Shutdown() override;
+
+  // Records a given event to be reported. Relevant settings will be checked to
+  // verify user events should be emitted and this will no-op if the the
+  // requisite permissions are not present.
+  void RecordUserEvent(std::unique_ptr<sync_pb::UserEventSpecifics> specifics);
+  void RecordUserEvent(const sync_pb::UserEventSpecifics& specifics);
+
+  base::WeakPtr<ModelTypeSyncBridge> GetSyncBridge();
+
+ private:
+  bool CanRecordEvent(const sync_pb::UserEventSpecifics& specifics);
+
+  SyncService* sync_service_;
+
+  std::unique_ptr<UserEventSyncBridge> bridge_;
+
+  // Holds onto a random number for the duration of this execution of chrome. On
+  // restart it will be regenerated. This can be attached to events to know
+  // which events came from the same session.
+  uint64_t session_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserEventService);
+};
+
+}  // namespace syncer
+
+#endif  // COMPONENTS_SYNC_USER_EVENTS_USER_EVENT_SERVICE_H_