Added support for improvement_direction to relevant values, which is propogated to chartjson.

tools/perf/benchmarks/jetstream.py

 # Copyright 2014 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.
 
 """Runs Apple's JetStream benchmark.
 
 JetStream combines a variety of JavaScript benchmarks, covering a variety of
 advanced workloads and programming techniques, and reports a single score that
 balances them using geometric mean.
 
@@ skipping 45 matching lines @@
     tab.EvaluateJavaScript('JetStream.start()')
     tab.WaitForJavaScriptExpression(get_results_js, 600)
 
     result = tab.EvaluateJavaScript(get_results_js)
     result = json.loads(result.partition(': ')[2])
 
     all_score_lists = []
     for k, v in result.iteritems():
       results.AddValue(list_of_scalar_values.ListOfScalarValues(
           results.current_page, k.replace('.', '_'), 'score', v['result'],
-          important=False))
+          important=False, higher_is_better=True))
       # Collect all test scores to compute geometric mean.
       for i, score in enumerate(v['result']):
         if len(all_score_lists) <= i:
           all_score_lists.append([])
         all_score_lists[i].append(score)
     all_scores = []
     for score_list in all_score_lists:
       all_scores.append(statistics.GeometricMean(score_list))
     results.AddSummaryValue(list_of_scalar_values.ListOfScalarValues(
         None, 'Score', 'score', all_scores))
 
 
 @benchmark.Disabled('android', 'xp')  # crbug.com/381742
 class Jetstream(benchmark.Benchmark):
   test = _JetstreamMeasurement
 
   def CreatePageSet(self, options):
     ps = page_set.PageSet(
         archive_data_file='../page_sets/data/jetstream.json',
         file_path=os.path.abspath(__file__),
         bucket=page_set.INTERNAL_BUCKET)
     ps.AddUserStory(page_module.Page(
         'http://browserbench.org/JetStream/', ps, ps.base_dir,
         make_javascript_deterministic=False))
     return ps