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

components/sync/driver/sync_service.h

Index: components/sync/driver/sync_service.h
diff --git a/components/sync/driver/sync_service.h b/components/sync/driver/sync_service.h
index ca749543676b6a7de3649a4ecdd401074540c1d3..dd53cb5cf05433e2d07eaa76e8e5b2942a5ac727 100644
--- a/components/sync/driver/sync_service.h
+++ b/components/sync/driver/sync_service.h
@@ -33,6 +33,7 @@ class BaseTransaction;
 class DataTypeController;
 class JsController;
 class LocalDeviceInfoProvider;
+class GlobalIdMapper;
 class ProtocolEventObserver;
 class SyncClient;
 class SyncCycleSnapshot;
@@ -353,6 +354,8 @@ class SyncService : public DataTypeEncryptionHandler, public KeyedService {
   // about the currently signed in user.
   virtual SigninManagerBase* signin() const = 0;
 
+  virtual GlobalIdMapper* GetGlobalIdMapper() const = 0;
+
  protected:
   SyncService() {}