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

tools/perf/benchmarks/maps.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 a Google Maps performance test.
 Rerforms several common navigation actions on the map (pan, zoom, rotate)"""
 
 import os
 import re
 
 from telemetry import benchmark
 from telemetry.core import util
 from telemetry.page import page as page_module
 from telemetry.page import page_set as page_set_module
 from telemetry.page import page_test
+from telemetry.value import improvement_direction
 from telemetry.value import scalar
 
 
 class _MapsMeasurement(page_test.PageTest):
   def __init__(self):
     super(_MapsMeasurement, self).__init__(
       action_name_to_run='RunPageInteractions')
 
   def ValidateAndMeasurePage(self, page, tab, results):
     js_get_results = 'document.getElementsByTagName("pre")[0].innerText'
     test_results = tab.EvaluateJavaScript(js_get_results)
 
     total = re.search('total=([0-9]+)', test_results).group(1)
     render = re.search('render=([0-9.]+),([0-9.]+)', test_results).group(2)
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'total_time', 'ms', total))
+        results.current_page, 'total_time', 'ms', total,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'render_mean_time', 'ms', render))
+        results.current_page, 'render_mean_time', 'ms', render,
+        improvement_direction=improvement_direction.DOWN))
 
 class MapsPage(page_module.Page):
   def __init__(self, page_set, base_dir):
     super(MapsPage, self).__init__(
         url='http://localhost:10020/tracker.html',
         page_set=page_set,
         base_dir=base_dir,
         make_javascript_deterministic=False)
 
   def RunNavigateSteps(self, action_runner):
@@ skipping 14 matching lines @@
         file_path=page_set_path)
     ps.AddUserStory(MapsPage(ps, ps.base_dir))
     return ps
 
 class MapsNoVsync(MapsBenchmark):
   """Runs the Google Maps benchmark with Vsync disabled"""
   tag = 'novsync'
 
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs('--disable-gpu-vsync')