Remove RelatedHistogramSet.

tracing/tracing/value/histogram_unittest.py

 # Copyright 2017 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 json
 import math
 import time
 import unittest
 
 from tracing.value import histogram
@@ skipping 936 matching lines @@
   def testMerge(self):
     events = histogram.RelatedEventSet()
     events.Add({
         'stableId': '0.0',
         'title': 'foo',
         'start': 0,
         'duration': 1,
     })
     generic = histogram.GenericSet(['generic diagnostic'])
     generic2 = histogram.GenericSet(['generic diagnostic 2'])
-    related_set = histogram.RelatedHistogramSet([
-        histogram.Histogram('histogram', 'count'),
-    ])
+    related_map = histogram.RelatedHistogramMap()
+    related_map.Set('a', histogram.Histogram('histogram', 'count'))
 
     hist = histogram.Histogram('', 'count')
 
     # When Histograms are merged, first an empty clone is created with an empty
     # DiagnosticMap.
     hist2 = histogram.Histogram('', 'count')
     hist2.diagnostics['a'] = generic
     hist.diagnostics.Merge(hist2.diagnostics, hist, hist2)
     self.assertIs(generic, hist.diagnostics['a'])
 
     # Separate keys are not merged.
     hist3 = histogram.Histogram('', 'count')
     hist3.diagnostics['b'] = generic2
     hist.diagnostics.Merge(hist3.diagnostics, hist, hist3)
     self.assertIs(generic, hist.diagnostics['a'])
     self.assertIs(generic2, hist.diagnostics['b'])
 
     # Merging unmergeable diagnostics should produce an
     # UnmergeableDiagnosticSet.
     hist4 = histogram.Histogram('', 'count')
-    hist4.diagnostics['a'] = related_set
+    hist4.diagnostics['a'] = related_map
     hist.diagnostics.Merge(hist4.diagnostics, hist, hist4)
     self.assertIsInstance(
         hist.diagnostics['a'], histogram.UnmergeableDiagnosticSet)
     diagnostics = list(hist.diagnostics['a'])
     self.assertIs(generic, diagnostics[0])
-    self.assertIs(related_set, diagnostics[1])
+    self.assertIs(related_map, diagnostics[1])
 
     # UnmergeableDiagnosticSets are mergeable.
     hist5 = histogram.Histogram('', 'count')
     hist5.diagnostics['a'] = histogram.UnmergeableDiagnosticSet(
         [events, generic2])
     hist.diagnostics.Merge(hist5.diagnostics, hist, hist5)
     self.assertIsInstance(
         hist.diagnostics['a'], histogram.UnmergeableDiagnosticSet)
     diagnostics = list(hist.diagnostics['a'])
     self.assertIs(generic, diagnostics[0])
-    self.assertIs(related_set, diagnostics[1])
+    self.assertIs(related_map, diagnostics[1])
     self.assertIs(events, diagnostics[2])
     self.assertIs(generic2, diagnostics[3])