[USS] implement CreateMetadataChangeList and GetClientTag

components/history/core/browser/typed_url_sync_metadata_database.h

Index: components/history/core/browser/typed_url_sync_metadata_database.h
diff --git a/components/history/core/browser/typed_url_sync_metadata_database.h b/components/history/core/browser/typed_url_sync_metadata_database.h
index 6967f48642d88e61e4162faca3e1b587b91dc9f2..0b687539c288ea57166f619ae5572fea2aa16251 100644
--- a/components/history/core/browser/typed_url_sync_metadata_database.h
+++ b/components/history/core/browser/typed_url_sync_metadata_database.h
@@ -8,7 +8,6 @@
 #include "base/macros.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/model/metadata_batch.h"
-#include "components/sync/model/sync_metadata_store.h"
 #include "sql/meta_table.h"
 
 namespace sql {
@@ -21,27 +20,30 @@ namespace history {
 // and datatype state table. Entity metadata table contains metadata(sync
 // states) for each url. Datatype state table contains the state of typed url
 // datatype.
-class TypedURLSyncMetadataDatabase : public syncer::SyncMetadataStore {
+class TypedURLSyncMetadataDatabase {
  public:
   // Must call InitVisitTable() before using to make sure the database is
   // initialized.
   TypedURLSyncMetadataDatabase();
-  ~TypedURLSyncMetadataDatabase() override;
+  virtual ~TypedURLSyncMetadataDatabase();
 
   // Read all the stored metadata for typed URL and fill |metadata_batch|
   // with it.
   bool GetAllSyncMetadata(syncer::MetadataBatch* metadata_batch);
 
-  // syncer::SyncMetadataStore implementation.
-  bool UpdateSyncMetadata(syncer::ModelType model_type,
-                          const std::string& storage_key,
-                          const sync_pb::EntityMetadata& metadata) override;
-  bool ClearSyncMetadata(syncer::ModelType model_type,
-                         const std::string& storage_key) override;
-  bool UpdateModelTypeState(
-      syncer::ModelType model_type,
-      const sync_pb::ModelTypeState& model_type_state) override;
-  bool ClearModelTypeState(syncer::ModelType model_type) override;
+  // Update the metadata row for typed URL, keyed by |storage_key|, to
+  // contain the contents of |metadata|.
+  bool UpdateSyncMetadata(const std::string& storage_key,
+                          const sync_pb::EntityMetadata& metadata);
+
+  // Remove the metadata row of typed URL keyed by |storage_key|.
+  bool ClearSyncMetadata(const std::string& storage_key);
+
+  // Update the stored sync state for the typed URL.
+  bool UpdateModelTypeState(const sync_pb::ModelTypeState& model_type_state);
+
+  // Clear the stored sync state for typed URL.
+  bool ClearModelTypeState();
 
  protected:
   // Returns the database for the functions in this interface.