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

content/browser/indexed_db/indexed_db_data_format_version.cc

Index: content/browser/indexed_db/indexed_db_data_format_version.cc
diff --git a/content/browser/indexed_db/indexed_db_data_format_version.cc b/content/browser/indexed_db/indexed_db_data_format_version.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b8a363cea5a842e5fef824103704e14158845297
--- /dev/null
+++ b/content/browser/indexed_db/indexed_db_data_format_version.cc
@@ -0,0 +1,16 @@
+// Copyright 2017 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.
+
+#include "content/browser/indexed_db/indexed_db_data_format_version.h"
+
+#include "third_party/WebKit/public/web/WebSerializedScriptValueVersion.h"
+
+namespace content {
+
+// static
+IndexedDBDataFormatVersion IndexedDBDataFormatVersion::current_(
+    0,
+    blink::kSerializedScriptValueVersion);
+
+}  // namespace content