[Telemetry] Introduce SummarizableValue.

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 story
 from telemetry.internal.results import page_test_results
 from telemetry.page import page as page_module
 from telemetry.timeline import async_slice
 from telemetry.timeline import model as model_module
+from telemetry.value import improvement_direction
 from telemetry.value import scalar
 from telemetry.web_perf.metrics import timeline_based_metric
 from telemetry.web_perf import timeline_based_measurement as tbm_module
 
 
 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))
 
 
 class TimelineBasedMetricTestData(object):
 
   def __init__(self, options):
     self._model = model_module.TimelineModel()
     renderer_process = self._model.GetOrCreateProcess(1)
     self._renderer_thread = renderer_process.GetOrCreateThread(2)
     self._renderer_thread.name = 'CrRendererMain'
     self._foo_thread = renderer_process.GetOrCreateThread(3)
@@ skipping 132 matching lines @@
 
   def testDuplicateRepeatableInteractions(self):
     d = TimelineBasedMetricTestData(self._options)
     d.AddInteraction(d.renderer_thread, ts=10, duration=5,
                      marker='Interaction.LogicalName/repeatable')
     d.AddInteraction(d.renderer_thread, ts=20, duration=5,
                      marker='Interaction.LogicalName/repeatable')
     d.FinalizeImport()
     d.AddResults()
     self.assertEquals(1, len(d.results.pages_that_succeeded))