Linkify sample Breakdowns via RelatedHistogramBreakdowns.

tracing/tracing/value/ui/diagnostic_span.html

Index: tracing/tracing/value/ui/diagnostic_span.html
diff --git a/tracing/tracing/value/ui/diagnostic_span.html b/tracing/tracing/value/ui/diagnostic_span.html
index 395b95e61390ae26a00ecef68b094550f4e95f15..ce3c31a3f18e448daa51b5385cbe3c6f9282f28a 100644
--- a/tracing/tracing/value/ui/diagnostic_span.html
+++ b/tracing/tracing/value/ui/diagnostic_span.html
@@ -67,7 +67,9 @@ tr.exportTo('tr.v.ui', function() {
   function createDiagnosticSpan(diagnostic, name, histogram) {
     const tagName = findElementNameForDiagnostic(diagnostic);
     const span = document.createElement(tagName);
-    if (span.build === undefined) throw new Error(tagName);
+    if (span.build === undefined) {
+      throw new Error(`Invalid diagnostic span "${tagName}"`);
+    }
     span.build(diagnostic, name, histogram);
     return span;
   }