Convert chart-json to Histograms.

tracing/bin/results2json

 #!/usr/bin/env python
 # 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.
 
 import argparse
 import json
 import sys
 import os
 
 tracing_path = os.path.abspath(os.path.join(
   os.path.dirname(os.path.realpath(__file__)), '..'))
 sys.path.append(tracing_path)
 from tracing import results_renderer
 
 
 def main():
   parser = argparse.ArgumentParser(
       description='Extract HistogramSet JSON from results2.html.',
       add_help=False)
   parser.add_argument('html_path', metavar='HTML_PATH',
                       help='HTML file path (input).')
   parser.add_argument('json_path', metavar='JSON_PATH',
                       help='JSON file path (input/output).')
   parser.add_argument('-h', '--help', action='help',
                       help='Show this help message and exit.')
   args = parser.parse_args()
 
-  histograms = results_renderer.ReadExistingResults(open(args.html_path, 'r'))
+  histograms = results_renderer.ReadExistingResults(
+      open(args.html_path, 'r').read())
   if os.path.exists(args.json_path):
     histograms.extend(json.load(open(args.json_path, 'r')))
   json.dump(histograms, open(args.json_path, 'w'))
 
 if __name__ == '__main__':
   sys.exit(main())