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

tools/telemetry/telemetry/web_perf/timeline_based_measurement_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 os
 import unittest
 
 from telemetry import decorators
 from telemetry.core import platform
 from telemetry.core import wpr_modes
 from telemetry.page import page as page_module
 from telemetry.page import page_set
 from telemetry.results import page_test_results
 from telemetry.timeline import model as model_module
 from telemetry.timeline import async_slice
 from telemetry.unittest_util import browser_test_case
 from telemetry.unittest_util import options_for_unittests
 from telemetry.unittest_util import page_test_test_case
+from telemetry.value import improvement_direction
 from telemetry.value import scalar
 from telemetry.web_perf import timeline_based_measurement as tbm_module
 from telemetry.web_perf import timeline_interaction_record as tir_module
 from telemetry.web_perf.metrics import timeline_based_metric
 
 
 class FakeFastMetric(timeline_based_metric.TimelineBasedMetric):
 
   def AddResults(self, model, renderer_thread, interaction_records, results):
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'FakeFastMetric', 'ms', 1))
+        results.current_page, 'FakeFastMetric', 'ms', 1,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'FastMetricRecords', 'count',
-        len(interaction_records)))
+        len(interaction_records),
+        improvement_direction=improvement_direction.DOWN))
 
 
 class FakeSmoothMetric(timeline_based_metric.TimelineBasedMetric):
 
   def AddResults(self, model, renderer_thread, interaction_records, results):
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'FakeSmoothMetric', 'ms', 1))
+        results.current_page, 'FakeSmoothMetric', 'ms', 1,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'SmoothMetricRecords', 'count',
-        len(interaction_records)))
+        len(interaction_records),
+        improvement_direction=improvement_direction.DOWN))
 
 
 class FakeLoadingMetric(timeline_based_metric.TimelineBasedMetric):
 
   def AddResults(self, model, renderer_thread, interaction_records, results):
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'FakeLoadingMetric', 'ms', 2))
+        results.current_page, 'FakeLoadingMetric', 'ms', 2,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'LoadingMetricRecords', 'count',
-        len(interaction_records)))
+        len(interaction_records),
+        improvement_direction=improvement_direction.DOWN))
 
 
 def GetMetricFromMetricType(metric_type):
   if metric_type == tir_module.IS_FAST:
     return FakeFastMetric()
   if metric_type == tir_module.IS_SMOOTH:
     return FakeSmoothMetric()
   if metric_type == tir_module.IS_RESPONSIVE:
     return FakeLoadingMetric()
   raise Exception('Unrecognized metric type: %s' % metric_type)
@@ skipping 223 matching lines @@
     # Since window.performance.now() uses wall-time instead of thread time,
     # we only assert the biggest jank > 50ms here to account for the fact
     # that the browser may deschedule during the jank loop.
     v = results.FindAllPageSpecificValuesNamed(
         'JankThreadJSRun-responsive-biggest_jank_thread_time')
     self.assertGreaterEqual(v[0].value, 50)
 
     v = results.FindAllPageSpecificValuesNamed(
         'JankThreadJSRun-responsive-total_big_jank_thread_time')
     self.assertGreaterEqual(v[0].value, 50)