Refactor Histogram relationship diagnostics.

tracing/tracing/value/ui/histogram_set_table_test.html

Index: tracing/tracing/value/ui/histogram_set_table_test.html
diff --git a/tracing/tracing/value/ui/histogram_set_table_test.html b/tracing/tracing/value/ui/histogram_set_table_test.html
index 9507871fff167c4d0c1d8d4c64ba220e046cede2..d5b83d7729f90a9af5986703cb16e5c19f9be4c9 100644
--- a/tracing/tracing/value/ui/histogram_set_table_test.html
+++ b/tracing/tracing/value/ui/histogram_set_table_test.html
@@ -96,9 +96,9 @@ tr.b.unittest.testSuite(function() {
     const histograms = new tr.v.HistogramSet();
     const aHist = histograms.createHistogram('a', tr.b.Unit.byName.count, [1]);
     const bHist = histograms.createHistogram('b', tr.b.Unit.byName.count, []);
-    const related = new tr.v.d.RelatedHistogramMap();
-    related.set('0', bHist);
-    aHist.diagnostics.set('r', related);
+    const related = new tr.v.d.Breakdown();
+    related.set('0', 0, bHist.name);
+    aHist.addSample(0, new Map([['r', related]]));
     const table = await buildTable(this, histograms);
     await table.viewState.tableRowStates.get('a').cells.get('Value').update(
       {isOpen: true});
@@ -162,9 +162,9 @@ tr.b.unittest.testSuite(function() {
     const histograms = new tr.v.HistogramSet();
     const aHist = histograms.createHistogram('a', tr.b.Unit.byName.count, [1]);
     const bHist = histograms.createHistogram('b', tr.b.Unit.byName.count, []);
-    const related = new tr.v.d.RelatedHistogramMap();
-    related.set('0', bHist);
-    aHist.diagnostics.set('r', related);
+    const related = new tr.v.d.Breakdown();
+    related.set('r', 0, bHist.name);
+    aHist.addSample(2, new Map([['r', related]]));
     const table = await buildTable(this, histograms);
 
     let cells = getNameCells(table);
@@ -986,10 +986,10 @@ tr.b.unittest.testSuite(function() {
               ]),
             });
 
-        const breakdown = new tr.v.d.RelatedHistogramBreakdown();
-        breakdown.add(aHist);
-        breakdown.add(bHist);
-        sourceHist.diagnostics.set('breakdown', breakdown);
+        const breakdown = new tr.v.d.Breakdown();
+        breakdown.set('a', 1, aHist.name);
+        breakdown.set('b', 1, bHist.name);
+        sourceHist.addSample(2, new Map([['breakdown', breakdown]]));
       }
     }
 
@@ -1171,10 +1171,10 @@ tr.b.unittest.testSuite(function() {
         'qux', tr.b.Unit.byName.timeDurationInMs_smallerIsBetter, [], {
           binBoundaries: TEST_BOUNDARIES,
         });
-    const breakdown = new tr.v.d.RelatedHistogramBreakdown();
-    breakdown.set('bar', barHist);
-    breakdown.set('qux', quxHist);
-    fooHist.diagnostics.set('breakdown', breakdown);
+    const breakdown = new tr.v.d.Breakdown();
+    breakdown.set('bar', 1, barHist.name);
+    breakdown.set('qux', 1, quxHist.name);
+    fooHist.addSample(2, new Map([['breakdown', breakdown]]));
 
     const table = await buildTable(this, histograms);