Block tree enhancements (prysmaticlabs#4764)

* Add votes, correct conversion and green for head

* Starting testing

* Fix for run time

beacon-chain/blockchain/info.go

@@ -79,17 +79,25 @@ func (s *Service) TreeHandler(w http.ResponseWriter, _ *http.Request) {
 	graph.Attr("labeljust", "l")
 
 	dotNodes := make([]*dot.Node, len(nodes))
+	avgBalance := uint64(averageBalance(s.headState.Balances()))
+
 	for i := len(nodes) - 1; i >= 0; i-- {
 		// Construct label for each node.
 		slot := strconv.Itoa(int(nodes[i].Slot))
-		weight := strconv.Itoa(int(nodes[i].Weight / 10e9))
+		weight := strconv.Itoa(int(nodes[i].Weight / 1e9)) // Convert unit Gwei to unit ETH.
+		votes := strconv.Itoa(int(nodes[i].Weight / 1e9 / avgBalance))
 		bestDescendent := strconv.Itoa(int(nodes[i].BestDescendent))
 		index := strconv.Itoa(int(i))
-		label := "slot: " + slot + "\n index: " + index + "\n bestDescendent: " + bestDescendent + "\n weight: " + weight
+		label := "slot: " + slot + "\n index: " + index + "\n bestDescendent: " + bestDescendent + "\n votes: " + votes + "\n weight: " + weight
 		var dotN dot.Node
 		if nodes[i].Parent != ^uint64(0) {
 			dotN = graph.Node(index).Box().Attr("label", label)
 		}
+
+		if nodes[i].Slot == s.headSlot {
+			dotN = dotN.Attr("color", "green")
+		}
+
 		dotNodes[i] = &dotN
 	}