[Sync] Maintain a global_id mapping to update UserEvents that references navigations

components/sync/driver/sync_service.h

 // 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.
 
 #ifndef COMPONENTS_SYNC_DRIVER_SYNC_SERVICE_H_
 #define COMPONENTS_SYNC_DRIVER_SYNC_SERVICE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 15 matching lines @@
 namespace sync_sessions {
 class OpenTabsUIDelegate;
 }  // namespace sync_sessions
 
 namespace syncer {
 
 class BaseTransaction;
 class DataTypeController;
 class JsController;
 class LocalDeviceInfoProvider;
+class GlobalIdMapper;
 class ProtocolEventObserver;
 class SyncClient;
 class SyncCycleSnapshot;
 class TypeDebugInfoObserver;
 struct SyncStatus;
 struct UserShare;
 
 // Events in ClearServerData flow to be recorded in histogram. Existing
 // constants should not be deleted or reordered. New ones shold be added at the
 // end, before CLEAR_SERVER_DATA_MAX.
@@ skipping 300 matching lines @@
   // For safety, the callback should be bound to some sort of WeakPtr<> or
   // scoped_refptr<>.
   virtual void GetAllNodes(
       const base::Callback<void(std::unique_ptr<base::ListValue>)>&
           callback) = 0;
 
   // Non-owning pointer to sign in logic that can be used to fetch information
   // about the currently signed in user.
   virtual SigninManagerBase* signin() const = 0;
 
+  virtual GlobalIdMapper* GetGlobalIdMapper() const = 0;
+
  protected:
   SyncService() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncService);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_DRIVER_SYNC_SERVICE_H_