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

tools/perf/benchmarks/indexeddb_perf.py

 # Copyright 2013 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 Chromium's IndexedDB performance test. These test:
 
 Databases:
   create/delete
 Keys:
   create/delete
@@ skipping 61 matching lines @@
     self._v8_object_stats_metric.AddResults(tab, results)
 
     js_get_results = "JSON.stringify(automation.getResults());"
     result_dict = json.loads(tab.EvaluateJavaScript(js_get_results))
     total = 0.0
     for key in result_dict:
       if key == 'OverallTestDuration':
         continue
       msec = float(result_dict[key])
       results.AddValue(scalar.ScalarValue(
-          results.current_page, key, 'ms', msec, important=False))
+          results.current_page, key, 'ms', msec, important=False,
+          higher_is_better=False))
 
       total += msec
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'Total Perf', 'ms', total))
+        results.current_page, 'Total Perf', 'ms', total,
+        higher_is_better=False))
 
 
   def CustomizeBrowserOptions(self, options):
     memory.MemoryMetric.CustomizeBrowserOptions(options)
     power.PowerMetric.CustomizeBrowserOptions(options)
     v8_object_stats.V8ObjectStatsMetric.CustomizeBrowserOptions(options)
 
 class IndexedDb(benchmark.Benchmark):
   """Chromium's IndexedDB Performance tests."""
   test = _IndexedDbMeasurement
 
   def CreatePageSet(self, options):
     indexeddb_dir = os.path.join(util.GetChromiumSrcDir(), 'chrome', 'test',
                                  'data', 'indexeddb')
     ps = page_set.PageSet(file_path=indexeddb_dir)
     ps.AddUserStory(page_module.Page('file://perf_test.html', ps, ps.base_dir))
     return ps