Use a two-part data format version in IndexedDB metadata.

content/common/indexed_db/indexed_db_struct_traits.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 CONTENT_COMMON_INDEXED_DB_INDEXED_DB_STRUCT_TRAITS_H_
 #define CONTENT_COMMON_INDEXED_DB_INDEXED_DB_STRUCT_TRAITS_H_
 
 #include "content/common/indexed_db/indexed_db.mojom.h"
 
 namespace mojo {
@@ skipping 121 matching lines @@
   }
   static MapValuesArrayView<int64_t, content::IndexedDBObjectStoreMetadata>
   object_stores(const content::IndexedDBDatabaseMetadata& metadata) {
     return MapValuesToArray(metadata.object_stores);
   }
   static bool Read(indexed_db::mojom::DatabaseMetadataDataView data,
                    content::IndexedDBDatabaseMetadata* out);
 };
 
 template <>
+struct StructTraits<indexed_db::mojom::DataFormatVersionDataView,
+                    content::IndexedDBDataFormatVersion> {
+  static uint64_t v8_version(
+      const content::IndexedDBDataFormatVersion& version) {
+    return version.v8_version();
+  }
+  static uint64_t blink_version(
+      const content::IndexedDBDataFormatVersion& version) {
+    return version.blink_version();
+  }
+  static bool Read(indexed_db::mojom::DataFormatVersionDataView data,
+                   content::IndexedDBDataFormatVersion* out);
+};
+
+template <>
 struct EnumTraits<indexed_db::mojom::CursorDirection,
                   blink::WebIDBCursorDirection> {
   static indexed_db::mojom::CursorDirection ToMojom(
       blink::WebIDBCursorDirection input);
   static bool FromMojom(indexed_db::mojom::CursorDirection input,
                         blink::WebIDBCursorDirection* output);
 };
 
 template <>
 struct EnumTraits<indexed_db::mojom::DataLoss, blink::WebIDBDataLoss> {
@@ skipping 30 matching lines @@
                   blink::WebIDBTransactionMode> {
   static indexed_db::mojom::TransactionMode ToMojom(
       blink::WebIDBTransactionMode input);
   static bool FromMojom(indexed_db::mojom::TransactionMode input,
                         blink::WebIDBTransactionMode* output);
 };
 
 }  // namespace mojo
 
 #endif  // CONTENT_COMMON_INDEXED_DB_INDEXED_DB_STRUCT_TRAITS_H_