Do not auto-open histograms in singular rows.

tracing/tracing/value/ui/histogram_set_table.html

Index: tracing/tracing/value/ui/histogram_set_table.html
diff --git a/tracing/tracing/value/ui/histogram_set_table.html b/tracing/tracing/value/ui/histogram_set_table.html
index 276b447a665583fde7d61a1e391fdab5d0b7e23b..86a990e9bb014860e12d54fd22f1d3be6cccf67b 100644
--- a/tracing/tracing/value/ui/histogram_set_table.html
+++ b/tracing/tracing/value/ui/histogram_set_table.html
@@ -577,12 +577,6 @@ tr.exportTo('tr.v.ui', function() {
       }
       this.checkNameColumnOverflow_();
 
-      if (this.isDisplayed && this.rows_.length === 1) {
-        for (let [displayLabel, cell] of this.rows_[0].cells) {
-          cell.isHistogramOpen = true;
-        }
-      }
-
       for (let row of this.rows_) {
         row.displayStatistic = this.displayStatistic;
       }
@@ -788,12 +782,6 @@ tr.exportTo('tr.v.ui', function() {
       this.isDisplayed = true;
 
       this.checkNameColumnOverflow_();
-
-      if (this.rows_ && this.rows_.length === 1) {
-        for (let [displayLabel, cell] of this.rows_[0].cells) {
-          cell.isHistogramOpen = true;
-        }
-      }
     },
 
     get constrainNameColumnWidth() {