xds: Remove EDS maybePublishConfig() avoidance in XdsDepManager (#12121)

The optimization makes the code more complicated. Yes, we know that
maybePublishConfig() will do no work because of an outstanding watch,
but we don't do this for other new watchers created and doing so would
just make the code more bug-prone. This removes a difference in how
different watcher types are handled.

Author: ejona86

xds/src/main/java/io/grpc/xds/XdsDependencyManager.java

@@ -456,17 +456,15 @@ public String toString() {
     return logId.toString();
   }
 
-  // Returns true if the watcher was added, false if it already exists
-  private boolean addEdsWatcher(String edsServiceName, CdsWatcher parentContext) {
+  private void addEdsWatcher(String edsServiceName, CdsWatcher parentContext) {
     EdsWatcher watcher
         = (EdsWatcher) getWatchers(XdsEndpointResource.getInstance()).get(edsServiceName);
     if (watcher != null) {
       watcher.addParentContext(parentContext); // Is a set, so don't need to check for existence
-      return false;
+      return;
     }
 
     addWatcher(new EdsWatcher(edsServiceName, parentContext));
-    return true;
   }
 
   private void addClusterWatcher(String clusterName, Object parentContext, int depth) {
@@ -823,13 +821,10 @@ public void onChanged(XdsClusterResource.CdsUpdate update) {
       switch (update.clusterType()) {
         case EDS:
           setData(update);
-          if (!addEdsWatcher(getEdsServiceName(), this))  {
-            maybePublishConfig();
-          }
+          addEdsWatcher(getEdsServiceName(), this);
           break;
         case LOGICAL_DNS:
           setData(update);
-          maybePublishConfig();
           // no eds needed
           break;
         case AGGREGATE:
@@ -856,27 +851,20 @@ public void onChanged(XdsClusterResource.CdsUpdate update) {
               setData(update);
               Set<String> addedClusters = Sets.difference(newNames, oldNames);
               addedClusters.forEach((cluster) -> addClusterWatcher(cluster, parentContext, depth));
-
-              if (addedClusters.isEmpty()) {
-                maybePublishConfig();
-              }
-            } else { // data was set to error status above
-              maybePublishConfig();
             }
 
           } else if (depth <= MAX_CLUSTER_RECURSION_DEPTH) {
             setData(update);
             update.prioritizedClusterNames()
                 .forEach(name -> addClusterWatcher(name, parentContext, depth));
-            maybePublishConfig();
           }
           break;
         default:
           Status error = Status.UNAVAILABLE.withDescription(
               "aggregate cluster graph exceeds max depth at " + resourceName() + nodeInfo());
           setDataAsStatus(error);
-          maybePublishConfig();
       }
+      maybePublishConfig();
     }
 
     public String getEdsServiceName() {