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

tools/telemetry/telemetry/value/histogram_unittest.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.
 import os
 import unittest
 
 from telemetry import page as page_module
 from telemetry import value
 from telemetry.page import page_set
 from telemetry.value import histogram as histogram_module
+from telemetry.value import improvement_direction
+from telemetry.value import summarizable
 
 
 class TestBase(unittest.TestCase):
   def setUp(self):
     ps = page_set.PageSet(file_path=os.path.dirname(__file__))
     ps.AddUserStory(page_module.Page("http://www.bar.com/", ps, ps.base_dir))
     ps.AddUserStory(page_module.Page("http://www.baz.com/", ps, ps.base_dir))
     ps.AddUserStory(page_module.Page("http://www.foo.com/", ps, ps.base_dir))
     self.page_set = ps
 
   @property
   def pages(self):
     return self.page_set.pages
 
 class ValueTest(TestBase):
   def testHistogramBasic(self):
     page0 = self.pages[0]
     histogram = histogram_module.HistogramValue(
         page0, 'x', 'counts',
         raw_value_json='{"buckets": [{"low": 1, "high": 2, "count": 1}]}',
-        important=False)
+        important=False, improvement_direction=improvement_direction.UP)
     self.assertEquals(
       ['{"buckets": [{"low": 1, "high": 2, "count": 1}]}'],
       histogram.GetBuildbotValue())
     self.assertEquals(1.5,
                       histogram.GetRepresentativeNumber())
     self.assertEquals(
       ['{"buckets": [{"low": 1, "high": 2, "count": 1}]}'],
       histogram.GetBuildbotValue())
 
     self.assertEquals(
@@ skipping 11 matching lines @@
     self.assertEquals(d, {
           'low': 33,
           'high': 45,
           'count': 78
         })
 
   def testAsDict(self):
     histogram = histogram_module.HistogramValue(
         None, 'x', 'counts',
         raw_value_json='{"buckets": [{"low": 1, "high": 2, "count": 1}]}',
-        important=False)
+        important=False, improvement_direction=improvement_direction.DOWN)
     d = histogram.AsDictWithoutBaseClassEntries()
 
     self.assertEquals(['buckets'], d.keys())
     self.assertTrue(isinstance(d['buckets'], list))
     self.assertEquals(len(d['buckets']), 1)
 
   def testFromDict(self):
     d = {
       'type': 'histogram',
       'name': 'x',
       'units': 'counts',
-      'buckets': [{'low': 1, 'high': 2, 'count': 1}]
+      'buckets': [{'low': 1, 'high': 2, 'count': 1}],
+      'improvement_direction': 'down',
     }
     v = value.Value.FromDict(d, {})
 
     self.assertTrue(isinstance(v, histogram_module.HistogramValue))
     self.assertEquals(
       ['{"buckets": [{"low": 1, "high": 2, "count": 1}]}'],
       v.GetBuildbotValue())
+    self.assertEquals(improvement_direction.DOWN, v.improvement_direction)