Add legacy plugin count to metrics

Spigot-Server-Patches/0005-Paper-Metrics.patch

@@ -15,15 +15,19 @@ decisions on behalf of the project.
 
 diff --git a/src/main/java/com/destroystokyo/paper/Metrics.java b/src/main/java/com/destroystokyo/paper/Metrics.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..f2a0a9f5d86820ce8098301256d2faf3d1a7c697
+index 0000000000000000000000000000000000000000..e4923ca371012188793b284cb0ed4280c31f50b6
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/Metrics.java
-@@ -0,0 +1,627 @@
+@@ -0,0 +1,664 @@
 +package com.destroystokyo.paper;
 +
 +import net.minecraft.server.MinecraftServer;
 +import org.bukkit.Bukkit;
 +import org.bukkit.configuration.file.YamlConfiguration;
++import org.bukkit.craftbukkit.util.CraftLegacy;
++import org.bukkit.craftbukkit.util.CraftMagicNumbers;
++import org.bukkit.plugin.Plugin;
++
 +import org.json.simple.JSONArray;
 +import org.json.simple.JSONObject;
 +
@@ -641,6 +645,39 @@ index 0000000000000000000000000000000000000000..f2a0a9f5d86820ce8098301256d2faf3
 +
 +                    return map;
 +                }));
++
++                metrics.addCustomChart(new Metrics.DrilldownPie("legacy_plugins", () -> {
++                    Map<String, Map<String, Integer>> map = new HashMap<>();
++
++                    // count legacy plugins
++                    int legacy = 0;
++                    for (Plugin plugin : Bukkit.getPluginManager().getPlugins()) {
++                        if (CraftMagicNumbers.isLegacy(plugin.getDescription())) {
++                            legacy++;
++                        }
++                    }
++
++                    // insert real value as lower dimension
++                    Map<String, Integer> entry = new HashMap<>();
++                    entry.put(String.valueOf(legacy), 1);
++
++                    // create buckets as higher dimension
++                    if (legacy == 0) {
++                        map.put("0 \uD83D\uDE0E", entry); // :sunglasses:
++                    } else if (legacy <= 5) {
++                        map.put("1-5", entry);
++                    } else if (legacy <= 10) {
++                        map.put("6-10", entry);
++                    } else if (legacy <= 25) {
++                        map.put("11-25", entry);
++                    } else if (legacy <= 50) {
++                        map.put("26-50", entry);
++                    } else {
++                        map.put("50+ \uD83D\uDE2D", entry); // :cry:
++                    }
++
++                    return map;
++                }));
 +            }
 +
 +        }

Spigot-Server-Patches/0437-Improved-Watchdog-Support.patch

@@ -41,10 +41,10 @@ This also moves all plugins who register "delayed init" tasks to occur just befo
 are properly accounted for and wont trip watchdog on init.
 
 diff --git a/src/main/java/com/destroystokyo/paper/Metrics.java b/src/main/java/com/destroystokyo/paper/Metrics.java
-index f2a0a9f5d86820ce8098301256d2faf3d1a7c697..8a19c96499c22f0d4705613ffec38d5677e1a72d 100644
+index e4923ca371012188793b284cb0ed4280c31f50b6..03c95b30d8a0557482d39468c058e7966114f824 100644
 --- a/src/main/java/com/destroystokyo/paper/Metrics.java
 +++ b/src/main/java/com/destroystokyo/paper/Metrics.java
-@@ -86,6 +86,9 @@ public class Metrics {
+@@ -90,6 +90,9 @@ public class Metrics {
          timer.scheduleAtFixedRate(new TimerTask() {
              @Override
              public void run() {