Re-encode bench mark source maps

This commit adds a small converter tool that can read scopes in an older
format and output it in the new format.

Author: szuend

bench/convert_maps.ts

@@ -0,0 +1,39 @@
+// Copyright 2025 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.
+
+/**
+ * @fileoverview Small utility that converts the scopes encoding of the
+ * source maps in the "maps/" directory from a given version to the currently
+ * checked out version.
+ *
+ * The given version must be a released version on JSR.
+ */
+
+import { expandGlob } from "jsr:@std/fs";
+import { parseArgs } from "jsr:@std/cli/parse-args";
+import { encode } from "../src/mod.ts";
+
+if (import.meta.main) {
+  const flags = parseArgs(Deno.args, {
+    string: ["from"]
+  });
+
+  if (!flags.from) {
+    throw new Error("--from is mandatory");
+  }
+
+  const oldCodec = await import(`jsr:@chrome-devtools/source-map-scopes-codec@${flags.from}`);
+
+  for await (
+    const file of expandGlob("maps/*.js.map", { root: import.meta.dirname })
+  ) {
+    const mapContent = Deno.readTextFileSync(file.path);
+    const mapJson = JSON.parse(mapContent);
+    const info = oldCodec.decode(mapJson);
+
+    encode(info, mapJson);
+
+    Deno.writeTextFileSync(file.path, JSON.stringify(mapJson));
+  }
+}