[Sync] Migrate bridge implementations to change list based MergeSyncData

components/reading_list/core/reading_list_store.h

 // Copyright 2016 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_READING_LIST_CORE_READING_LIST_STORE_H_
 #define COMPONENTS_READING_LIST_CORE_READING_LIST_STORE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 30 matching lines @@
   void RemoveEntry(const ReadingListEntry& entry) override;
 
   // Creates an object used to communicate changes in the sync metadata to the
   // model type store.
   std::unique_ptr<syncer::MetadataChangeList> CreateMetadataChangeList()
       override;
 
   // Perform the initial merge between local and sync data. This should only be
   // called when a data type is first enabled to start syncing, and there is no
   // sync metadata. Best effort should be made to match local and sync data. The
-  // keys in the |entity_data_map| will have been created via GetClientTag(...),
-  // and if a local and sync data should match/merge but disagree on tags, the
-  // service should use the sync data's tag. Any local pieces of data that are
-  // not present in sync should immediately be Put(...) to the processor before
-  // returning. The same MetadataChangeList that was passed into this function
-  // can be passed to Put(...) calls. Delete(...) can also be called but should
-  // not be needed for most model types. Durable storage writes, if not able to
-  // combine all change atomically, should save the metadata after the data
-  // changes, so that this merge will be re-driven by sync if is not completely
-  // saved during the current run.
+  // storage keys in the |entity_data| are populated with GetStorageKey(...),
+  // local and sync copies of the same entity should resolve to the same storage
+  // key. Any local pieces of data that are not present in sync should
+  // immediately be Put(...) to the processor before returning. The same
+  // MetadataChangeList that was passed into this function can be passed to
+  // Put(...) calls. Delete(...) can also be called but should not be needed for
+  // most model types. Durable storage writes, if not able to combine all change
+  // atomically, should save the metadata after the data changes, so that this
+  // merge will be re-driven by sync if is not completely saved during the
+  // current run.
   base::Optional<syncer::ModelError> MergeSyncData(
       std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
-      syncer::EntityDataMap entity_data_map) override;
+      syncer::EntityChangeList entity_data) override;
 
   // Apply changes from the sync server locally.
   // Please note that |entity_changes| might have fewer entries than
   // |metadata_change_list| in case when some of the data changes are filtered
   // out, or even be empty in case when a commit confirmation is processed and
   // only the metadata needs to persisted.
   base::Optional<syncer::ModelError> ApplySyncChanges(
       std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
       syncer::EntityChangeList entity_changes) override;
 
@@ skipping 92 matching lines @@
   std::unique_ptr<syncer::ModelTypeStore::WriteBatch> batch_;
 
   base::Clock* clock_;
 
   SEQUENCE_CHECKER(sequence_checker_);
 
   DISALLOW_COPY_AND_ASSIGN(ReadingListStore);
 };
 
 #endif  // COMPONENTS_READING_LIST_CORE_READING_LIST_STORE_H_