[Sync] Migrate bridge implementations to change list based MergeSyncData

components/sync/user_events/user_event_sync_bridge.cc

 // 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.
 
 #include "components/sync/user_events/user_event_sync_bridge.h"
 
 #include <utility>
 
 #include "base/big_endian.h"
 #include "base/bind.h"
@@ skipping 58 matching lines @@
 
 UserEventSyncBridge::~UserEventSyncBridge() {}
 
 std::unique_ptr<MetadataChangeList>
 UserEventSyncBridge::CreateMetadataChangeList() {
   return WriteBatch::CreateMetadataChangeList();
 }
 
 base::Optional<ModelError> UserEventSyncBridge::MergeSyncData(
     std::unique_ptr<MetadataChangeList> metadata_change_list,
-    EntityDataMap entity_data_map) {
+    EntityChangeList entity_data) {
   NOTREACHED();
   return {};
 }
 
 base::Optional<ModelError> UserEventSyncBridge::ApplySyncChanges(
     std::unique_ptr<MetadataChangeList> metadata_change_list,
     EntityChangeList entity_changes) {
   std::unique_ptr<WriteBatch> batch = store_->CreateWriteBatch();
   for (EntityChange& change : entity_changes) {
     DCHECK_EQ(EntityChange::ACTION_DELETE, change.type());
@@ skipping 123 matching lines @@
   std::unique_ptr<WriteBatch> batch = store_->CreateWriteBatch();
   for (const Record& r : *data_records) {
     batch->DeleteData(r.id);
   }
   store_->CommitWriteBatch(
       std::move(batch),
       base::Bind(&UserEventSyncBridge::OnCommit, base::AsWeakPtr(this)));
 }
 
 }  // namespace syncer