Refactor diagnostic spans to share a polymer behavior.

tracing/tracing/value/ui/related_histogram_set_span.html

Index: tracing/tracing/value/ui/related_histogram_set_span.html
diff --git a/tracing/tracing/value/ui/related_histogram_set_span.html b/tracing/tracing/value/ui/related_histogram_set_span.html
index 0cc3907f484222e867b1e2018be015d53ad7076d..741968a4af8194332951ecfa80a297cfd21a9980 100644
--- a/tracing/tracing/value/ui/related_histogram_set_span.html
+++ b/tracing/tracing/value/ui/related_histogram_set_span.html
@@ -6,25 +6,17 @@ found in the LICENSE file.
 -->
 
 <link rel="import" href="/tracing/ui/analysis/analysis_link.html">
+<link rel="import" href="/tracing/value/ui/diagnostic_span_behavior.html">
 
 <dom-module id="tr-v-ui-related-histogram-set-span">
-  <script>
-  'use strict';
+</dom-module>
+
+<script>
+'use strict';
+tr.exportTo('tr.v.ui', function() {
   Polymer({
     is: 'tr-v-ui-related-histogram-set-span',
-
-    ready() {
-      this.diagnostic_ = undefined;
-    },
-
-    get diagnostic() {
-      return this.diagnostic_;
-    },
-
-    set diagnostic(d) {
-      this.diagnostic_ = d;
-      this.updateContents_();
-    },
+    behaviors: [tr.v.ui.DIAGNOSTIC_SPAN_BEHAVIOR],
 
     addLink_(selection, content) {
       const link = document.createElement('tr-ui-a-analysis-link');
@@ -49,5 +41,8 @@ found in the LICENSE file.
       }
     }
   });
-  </script>
-</dom-module>
+
+  return {
+  };
+});
+</script>