[sync] skeleton implementation of TypedURLSyncBridge

components/history/core/browser/history_service.h

Index: components/history/core/browser/history_service.h
diff --git a/components/history/core/browser/history_service.h b/components/history/core/browser/history_service.h
index 799217af7b2bf1fe992183bef9c0988d2384e17c..9e44870453cab9e894d31ac083b681497cf583a0 100644
--- a/components/history/core/browser/history_service.h
+++ b/components/history/core/browser/history_service.h
@@ -33,6 +33,7 @@
 #include "components/history/core/browser/delete_directive_handler.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/history/core/browser/keyword_id.h"
+#include "components/history/core/browser/typed_url_sync_bridge.h"
 #include "components/history/core/browser/typed_url_syncable_service.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/sync/model/syncable_service.h"
@@ -129,6 +130,11 @@ class HistoryService : public syncer::SyncableService, public KeyedService {
   // They return false if database is not available (e.g. not loaded yet) or the
   // URL does not exist.
 
+  // Returns a pointer to the TypedURLSyncBridge owned by HistoryBackend.
+  // This method should only be called from the history thread, because the
+  // returned bridge is intended to be accessed only via the history thread.
+  TypedURLSyncBridge* GetTypedURLSyncBridge() const;
+
   // Returns a pointer to the TypedUrlSyncableService owned by HistoryBackend.
   // This method should only be called from the history thread, because the
   // returned service is intended to be accessed only via the history thread.