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

tools/telemetry/telemetry/user_story/user_story_runner_unittest.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.
 
 import unittest
 import StringIO
 import sys
 
 from telemetry import benchmark
 from telemetry import user_story
 from telemetry.core import exceptions
 from telemetry.page import page as page_module
 from telemetry.page import page_test
 from telemetry.page import test_expectations
 from telemetry.results import results_options
 from telemetry.unittest_util import options_for_unittests
 from telemetry.unittest_util import system_stub
 from telemetry.user_story import shared_user_story_state
 from telemetry.user_story import user_story_runner
 from telemetry.user_story import user_story_set
 from telemetry.util import cloud_storage
 from telemetry.util import exception_formatter as exception_formatter_module
+from telemetry.value import improvement_direction
 from telemetry.value import scalar
 from telemetry.value import string
 from telemetry.web_perf import timeline_based_measurement
 
 # This linter complains if we define classes nested inside functions.
 # pylint: disable=bad-super-call
 
 
 class FakePlatform(object):
   def CanMonitorThermalThrottling(self):
@@ skipping 367 matching lines @@
   def testPagesetRepeat(self):
     us = user_story_set.UserStorySet()
     us.AddUserStory(DummyLocalUserStory(TestSharedPageState, name='blank'))
     us.AddUserStory(DummyLocalUserStory(TestSharedPageState, name='green'))
 
     class Measurement(page_test.PageTest):
       i = 0
       def RunPage(self, page, _, results):
         self.i += 1
         results.AddValue(scalar.ScalarValue(
-            page, 'metric', 'unit', self.i))
+            page, 'metric', 'unit', self.i,
+            improvement_direction=improvement_direction.UP))
 
       def ValidateAndMeasurePage(self, page, tab, results):
         pass
 
     self.options.page_repeat = 1
     self.options.pageset_repeat = 2
     self.options.output_formats = ['buildbot']
     output = StringIO.StringIO()
     real_stdout = sys.stdout
     sys.stdout = output
@@ skipping 127 matching lines @@
         num_failing_user_stories=5, runner_max_failures=3,
         options_max_failures=None, expected_num_failures=4)
 
   def testMaxFailuresOption(self):
     # Runs up to max_failures+1 failing tests before stopping, since
     # every tests after max_failures failures have been encountered
     # may all be passing.
     self._testMaxFailuresOptionIsRespectedAndOverridable(
         num_failing_user_stories=5, runner_max_failures=3,
         options_max_failures=1, expected_num_failures=2)