Create and display "comparison statistics" to compare two statistics

tools/telemetry/telemetry/page/buildbot_page_measurement_results_unittest.py

Index: tools/telemetry/telemetry/page/buildbot_page_measurement_results_unittest.py
diff --git a/tools/telemetry/telemetry/page/buildbot_page_measurement_results_unittest.py b/tools/telemetry/telemetry/page/buildbot_page_measurement_results_unittest.py
index 6854eda8ab36aa0b29d6d6bcb019089235a81f7b..2f8dc9cbe7cc9f38020382cff4890cb756f684fa 100644
--- a/tools/telemetry/telemetry/page/buildbot_page_measurement_results_unittest.py
+++ b/tools/telemetry/telemetry/page/buildbot_page_measurement_results_unittest.py
@@ -5,6 +5,7 @@ import os
 import unittest
 
 from telemetry.page import buildbot_page_measurement_results
+from telemetry.page import page_measurement_value
 from telemetry.page import page_set
 from telemetry.page import perf_tests_helper
 
@@ -29,6 +30,9 @@ class SummarySavingPageMeasurementResults(
     res = perf_tests_helper.PrintPerfResult(*args, print_to_stdout=False)
     self.results.append(res)
 
+  def GetComparisonStats(self):
+    return self._comparison_stats
+
 class BuildbotPageMeasurementResultsTest(unittest.TestCase):
   def test_basic_summary(self):
     test_page_set = _MakePageSet()
@@ -337,3 +341,70 @@ class BuildbotPageMeasurementResultsTest(unittest.TestCase):
         'RESULT telemetry_page_measurement_results: num_failed= 0 count',
         'RESULT telemetry_page_measurement_results: num_errored= 0 count']
     self.assertEquals(measurement_results.results, expected)
+
+  def test_comparison_byname_devolution(self):
+    test_page_set = _MakePageSet()
+
+    measurement_results = SummarySavingPageMeasurementResults()
+
+    measurement_results.AddComparison('a', '', 'b', '', 'c', '')
+
+    aName = page_measurement_value.MeasurementName('', 'a')
+    bName = page_measurement_value.MeasurementName('', 'b')
+    cName = page_measurement_value.MeasurementName('', 'c')
+    topStat = { 'reference' : aName, 'comparison' : bName }
+
+    compStats = measurement_results.GetComparisonStats()
+    self.assertEquals(set(compStats.keys()), set([cName,]))
+    self.assertEquals(compStats[cName], topStat)
+
+    measurement_results.WillMeasurePage(test_page_set.pages[0])
+    measurement_results.Add('a', 'seconds', 3)
+    measurement_results.DidMeasurePage()
+    measurement_results.WillMeasurePage(test_page_set.pages[0])
+    measurement_results.Add('b', 'seconds', 5)
+    measurement_results.DidMeasurePage()
+
+    measurement_results.WillMeasurePage(test_page_set.pages[1])
+    measurement_results.Add('a', 'seconds', 7)
+    measurement_results.DidMeasurePage()
+    measurement_results.WillMeasurePage(test_page_set.pages[1])
+    measurement_results.Add('b', 'seconds', 14)
+    measurement_results.DidMeasurePage()
+
+    measurement_results.PrintSummary()
+    expected = ['RESULT a_by_url: http___www.foo.com_= 3 seconds',
+                'RESULT a_by_url: http___www.bar.com_= 7 seconds',
+                '*RESULT a: a= [3,7] seconds\nAvg a: 5.000000seconds\n' +
+                'Sd  a: 2.828427seconds',
+                'RESULT b_by_url: http___www.foo.com_= 5 seconds',
+                'RESULT b_by_url: http___www.bar.com_= 14 seconds',
+                '*RESULT b: b= [5,14] seconds\nAvg b: 9.500000seconds\n' +
+                'Sd  b: 6.363961seconds',
+                'RESULT telemetry_page_measurement_results: ' +
+                'num_failed= 0 count',
+                'RESULT telemetry_page_measurement_results: ' +
+                'num_errored= 0 count']
+
+    self.assertEquals(measurement_results.results, expected)
+
+    fooName = page_measurement_value.MeasurementName(
+      'c_by_url', 'http://www.foo.com/')
+    barName = page_measurement_value.MeasurementName(
+      'c_by_url', 'http://www.bar.com/')
+    fooStat = { 'reference' : page_measurement_value.MeasurementName(
+        'a_by_url', 'http://www.foo.com/'),
+                'comparison' : page_measurement_value.MeasurementName(
+        'b_by_url', 'http://www.foo.com/') }
+    barStat = { 'reference' : page_measurement_value.MeasurementName(
+        'a_by_url', 'http://www.bar.com/'),
+                'comparison' : page_measurement_value.MeasurementName(
+        'b_by_url', 'http://www.bar.com/') }
+
+    compStats = measurement_results.GetComparisonStats()
+    self.assertEquals(set(compStats.keys()), set([cName, fooName, barName]))
+    self.assertEquals(compStats[cName], topStat)
+    self.assertEquals(compStats[fooName], fooStat)
+    self.assertEquals(compStats[barName], barStat)
+
+