[Sync] USS: Implement SimpleMetadataChangeList.

BUG=

Review URL: https://codereview.chromium.org/1691013002

Cr-Commit-Position: refs/heads/master@{#375978}

2 files changed, 48 insertions, 8 deletions

diff --git a/sync/internal_api/public/simple_metadata_change_list.cc b/sync/internal_api/public/simple_metadata_change_list.cc
index 999eda6..e358dda 100644
--- a/sync/internal_api/public/simple_metadata_change_list.cc
+++ b/sync/internal_api/public/simple_metadata_change_list.cc
@@ -12,24 +12,38 @@ SimpleMetadataChangeList::~SimpleMetadataChangeList() {}
 
 void SimpleMetadataChangeList::UpdateDataTypeState(
     const sync_pb::DataTypeState& data_type_state) {
-  // TODO(skym): Implementation.
+  state_change_.reset(new DataTypeStateChange{UPDATE, data_type_state});
+}
+
+void SimpleMetadataChangeList::ClearDataTypeState() {
+  state_change_.reset(new DataTypeStateChange{CLEAR});
 }
 
 void SimpleMetadataChangeList::UpdateMetadata(
     const std::string& client_tag,
     const sync_pb::EntityMetadata& metadata) {
-  // TODO(skym): Implementation.
+  metadata_changes_[client_tag] = {UPDATE, metadata};
 }
 
-void SimpleMetadataChangeList::ClearDataTypeState() {
-  // TODO(skym): Implementation.
+void SimpleMetadataChangeList::ClearMetadata(const std::string& client_tag) {
+  metadata_changes_[client_tag] = {CLEAR, sync_pb::EntityMetadata()};
 }
 
-void SimpleMetadataChangeList::ClearMetadata(const std::string& client_tag) {
-  // TODO(skym): Implementation.
+const SimpleMetadataChangeList::MetadataChanges&
+SimpleMetadataChangeList::GetMetadataChanges() const {
+  return metadata_changes_;
+}
+
+bool SimpleMetadataChangeList::HasDataTypeStateChange() const {
+  return state_change_.get() != nullptr;
+}
+
+const SimpleMetadataChangeList::DataTypeStateChange&
+SimpleMetadataChangeList::GetDataTypeStateChange() const {
+  return *state_change_.get();
 }
 
-void SimpleMetadataChangeList::TranfserChanges(
+void SimpleMetadataChangeList::TransferChanges(
     ModelTypeStore* store,
     ModelTypeStore::WriteBatch* write_batch) {
   // TODO(skym): Implementation.
diff --git a/sync/internal_api/public/simple_metadata_change_list.h b/sync/internal_api/public/simple_metadata_change_list.h
index f302b12..9daaee4 100644
--- a/sync/internal_api/public/simple_metadata_change_list.h
+++ b/sync/internal_api/public/simple_metadata_change_list.h
@@ -5,11 +5,15 @@
 #ifndef SYNC_INTERNAL_API_PUBLIC_SIMPLE_METADATA_CHANGE_LIST_H_
 #define SYNC_INTERNAL_API_PUBLIC_SIMPLE_METADATA_CHANGE_LIST_H_
 
+#include <map>
 #include <string>
 
 #include "sync/api/metadata_change_list.h"
 #include "sync/api/model_type_store.h"
 #include "sync/base/sync_export.h"
+#include "sync/internal_api/public/non_blocking_sync_common.h"
+#include "sync/protocol/data_type_state.pb.h"
+#include "sync/protocol/entity_metadata.pb.h"
 
 namespace syncer_v2 {
 
@@ -18,6 +22,20 @@ namespace syncer_v2 {
 // requested transfers them to the store/write batch.
 class SYNC_EXPORT SimpleMetadataChangeList : public MetadataChangeList {
  public:
+  enum ChangeType { UPDATE, CLEAR };
+
+  struct MetadataChange {
+    ChangeType type;
+    sync_pb::EntityMetadata metadata;
+  };
+
+  struct DataTypeStateChange {
+    ChangeType type;
+    sync_pb::DataTypeState state;
+  };
+
+  typedef std::map<std::string, MetadataChange> MetadataChanges;
+
   SimpleMetadataChangeList();
   ~SimpleMetadataChangeList() override;
 
@@ -28,11 +46,19 @@ class SYNC_EXPORT SimpleMetadataChangeList : public MetadataChangeList {
                       const sync_pb::EntityMetadata& metadata) override;
   void ClearMetadata(const std::string& client_tag) override;
 
+  const MetadataChanges& GetMetadataChanges() const;
+  bool HasDataTypeStateChange() const;
+  const DataTypeStateChange& GetDataTypeStateChange() const;
+
   // Moves all currently accumulated changes into the write batch, clear out
   // local copies. Calling this multiple times will work, but should not be
   // necessary.
-  void TranfserChanges(ModelTypeStore* store,
+  void TransferChanges(ModelTypeStore* store,
                        ModelTypeStore::WriteBatch* write_batch);
+
+ private:
+  MetadataChanges metadata_changes_;
+  scoped_ptr<DataTypeStateChange> state_change_;
 };
 
 }  // namespace syncer_v2