Use MetadataChangeList and EntityChangeList in SharedModelTypeProcessor

sync/internal_api/public/test/fake_metadata_change_list.h

Index: sync/internal_api/public/test/fake_metadata_change_list.h
diff --git a/sync/internal_api/public/test/fake_metadata_change_list.h b/sync/internal_api/public/test/fake_metadata_change_list.h
new file mode 100644
index 0000000000000000000000000000000000000000..6359602ac96532533f4f3f97f748bfeca7db2826
--- /dev/null
+++ b/sync/internal_api/public/test/fake_metadata_change_list.h
@@ -0,0 +1,57 @@
+// 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 SYNC_INTERNAL_API_PUBLIC_TEST_FAKE_METADATA_CHANGE_LIST_H_
+#define SYNC_INTERNAL_API_PUBLIC_TEST_FAKE_METADATA_CHANGE_LIST_H_
+
+#include <vector>
+
+#include "sync/api/metadata_change_list.h"
+#include "sync/internal_api/public/non_blocking_sync_common.h"
+#include "sync/protocol/entity_metadata.pb.h"
+
+namespace syncer_v2 {
+
+// A non-functional implementation of MetadataChangeList for
+// testing purposes.
+// This class simply records all calls with all arguments for further
+// analysis by the test code.
+class FakeMetadataChangeList : public MetadataChangeList {
+ public:
+  FakeMetadataChangeList();
+  ~FakeMetadataChangeList() override;
+
+  void UpdateDataTypeState(const DataTypeState& data_type_state) override;
+  void ClearDataTypeState() override;
+  void UpdateMetadata(const std::string& client_tag,
+                      const sync_pb::EntityMetadata& metadata) override;
+  void ClearMetadata(const std::string& client_tag) override;
+
+  enum Action {
+    UPDATE_DATA_TYPE_STATE,
+    CLEAR_DATA_TYPE_STATE,
+    UPDATE_METADATA,
+    CLEAR_METADATA
+  };
+
+  struct Record {
+    Record();
+    virtual ~Record();
+
+    Action action;
+    std::string tag;
+    DataTypeState data_type_state;
+    sync_pb::EntityMetadata metadata;
+  };
+
+  size_t GetNumRecords() const;
+  const Record& GetNthRecord(size_t n) const;
+
+ private:
+  std::vector<Record> records_;
+};
+
+}  // namespace syncer_v2
+
+#endif  // SYNC_INTERNAL_API_PUBLIC_TEST_FAKE_METADATA_CHANGE_LIST_H_