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

tools/perf/benchmarks/kraken.py

 # Copyright 2012 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 Mozilla's Kraken JavaScript benchmark."""
 
 import os
 
 from metrics import power
 from telemetry import benchmark
@@ skipping 81 matching lines @@
         var formElement = document.getElementsByTagName("input")[0];
         decodeURIComponent(formElement.value.split("?")[1]);
         """
     result_dict = eval(tab.EvaluateJavaScript(js_get_results))
     total = 0
     for key in result_dict:
       if key == 'v':
         continue
       results.AddValue(list_of_scalar_values.ListOfScalarValues(
           results.current_page, key, 'ms', result_dict[key], important=False,
-          description=DESCRIPTIONS.get(key)))
+          description=DESCRIPTIONS.get(key), higher_is_better=False))
       total += _Mean(result_dict[key])
 
     # TODO(tonyg/nednguyen): This measurement shouldn't calculate Total. The
     # results system should do that for us.
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'Total', 'ms', total,
         description='Total of the means of the results for each type '
                     'of benchmark in [Mozilla\'s Kraken JavaScript benchmark]'
-                    '(http://krakenbenchmark.mozilla.org/)'))
+                    '(http://krakenbenchmark.mozilla.org/)',
+        higher_is_better=False))
 
 
 class Kraken(benchmark.Benchmark):
   """Mozilla's Kraken JavaScript benchmark."""
   test = _KrakenMeasurement
 
   def CreatePageSet(self, options):
     ps = page_set.PageSet(
       archive_data_file='../page_sets/data/kraken.json',
       file_path=os.path.abspath(__file__),
       bucket=page_set.PARTNER_BUCKET)
     ps.AddUserStory(page_module.Page(
         'http://krakenbenchmark.mozilla.org/kraken-1.1/driver.html',
         ps, ps.base_dir))
     return ps