[Sync] ApplySyncChanges autofill implementation.

components/autofill/core/browser/webdata/autofill_metadata_change_list.cc

Index: components/autofill/core/browser/webdata/autofill_metadata_change_list.cc
diff --git a/components/autofill/core/browser/webdata/autofill_metadata_change_list.cc b/components/autofill/core/browser/webdata/autofill_metadata_change_list.cc
index 5126c27de142f67ca7340b1d26640b5a74b38444..24876e4a0cff1b7dd51b5dec518717e20ec9dae8 100644
--- a/components/autofill/core/browser/webdata/autofill_metadata_change_list.cc
+++ b/components/autofill/core/browser/webdata/autofill_metadata_change_list.cc
@@ -6,7 +6,8 @@
 
 #include "base/location.h"
 
-using syncer::SyncError;
+using base::Optional;
+using syncer::ModelError;
 
 namespace autofill {
 
@@ -19,60 +20,56 @@ AutofillMetadataChangeList::AutofillMetadataChangeList(AutofillTable* table,
 }
 
 AutofillMetadataChangeList::~AutofillMetadataChangeList() {
-  DCHECK(!error_.IsSet());
+  DCHECK(!error_);
 }
 
 void AutofillMetadataChangeList::UpdateModelTypeState(
     const sync_pb::ModelTypeState& model_type_state) {
-  if (error_.IsSet()) {
+  if (error_) {
     return;
   }
 
   if (!table_->UpdateModelTypeState(type_, model_type_state)) {
-    error_ = SyncError(FROM_HERE, SyncError::DATATYPE_ERROR,
-                       "Failed to update ModelTypeState.", type_);
+    error_ = ModelError(FROM_HERE, "Failed to update ModelTypeState.");
   }
 }
 
 void AutofillMetadataChangeList::ClearModelTypeState() {
-  if (error_.IsSet()) {
+  if (error_) {
     return;
   }
 
   if (!table_->ClearModelTypeState(type_)) {
-    error_ = SyncError(FROM_HERE, SyncError::DATATYPE_ERROR,
-                       "Failed to clear ModelTypeState.", type_);
+    error_ = ModelError(FROM_HERE, "Failed to clear ModelTypeState.");
   }
 }
 
 void AutofillMetadataChangeList::UpdateMetadata(
     const std::string& storage_key,
     const sync_pb::EntityMetadata& metadata) {
-  if (error_.IsSet()) {
+  if (error_) {
     return;
   }
 
   if (!table_->UpdateSyncMetadata(type_, storage_key, metadata)) {
-    error_ = SyncError(FROM_HERE, SyncError::DATATYPE_ERROR,
-                       "Failed to update entity metadata.", type_);
+    error_ = ModelError(FROM_HERE, "Failed to update entity metadata.");
   }
 }
 
 void AutofillMetadataChangeList::ClearMetadata(const std::string& storage_key) {
-  if (error_.IsSet()) {
+  if (error_) {
     return;
   }
 
   if (!table_->ClearSyncMetadata(type_, storage_key)) {
-    error_ = SyncError(FROM_HERE, SyncError::DATATYPE_ERROR,
-                       "Failed to clear entity metadata.", type_);
+    error_ = ModelError(FROM_HERE, "Failed to clear entity metadata.");
   }
 }
 
-SyncError AutofillMetadataChangeList::TakeError() {
-  SyncError e = error_;
-  error_ = SyncError();
-  return e;
+Optional<ModelError> AutofillMetadataChangeList::TakeError() {
+  Optional<ModelError> temp = error_;
+  error_.reset();
+  return temp;
 }
 
 }  // namespace autofill