Fix sizes script conversion error

Fixes an issue in the sizes script when converting from ChartJSON to
HistogramSet. The data produced by the results collector does not
contain the benchmark_name or format_version keys, which causes the
conversion script to fail.

Bug: 906685

Change-Id: I15258026651499ac2a7640958c7bd2d93a794a35
Reviewed-on: https://chromium-review.googlesource.com/c/1352395
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612511}

infra/scripts/legacy/scripts/slave/chromium/sizes.py

@@ -602,8 +602,15 @@ def main():
 
   if options.output_dir:
     histogram_path = os.path.join(options.output_dir, 'perf_results.json')
+    # We need to add a bit more data to the results, otherwise the conversion
+    # fails due to the provided data being malformed.
+    updated_results = {
+      'format_version': '1.0',
+      'benchmark_name': 'sizes',
+      'charts': results_collector.results,
+    }
     with open(histogram_path, 'w') as f:
-      json.dump(results_collector.results, f)
+      json.dump(updated_results, f)
     histogram_result = convert_chart_json.ConvertChartJson(histogram_path)
     if histogram_result.returncode != 0:
       sys.stderr.write(