core: change service config to ConfigOrError

Both the config and the error need to be passed to the managed channel so it can decide to keep or reject the config. Passing only the parsed object means the managed channel cannot implement the error handling gRFC.

core/src/main/java/io/grpc/NameResolver.java

@@ -21,6 +21,7 @@
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
+import io.grpc.NameResolver.Helper.ConfigOrError;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -419,12 +420,12 @@ public static final class ResolutionResult {
     @ResolutionResultAttr
     private final Attributes attributes;
     @Nullable
-    private final Object serviceConfig;
+    private final ConfigOrError serviceConfig;
 
     ResolutionResult(
         List<EquivalentAddressGroup> servers,
         @ResolutionResultAttr Attributes attributes,
-        Object serviceConfig) {
+        ConfigOrError serviceConfig) {
       this.servers = Collections.unmodifiableList(new ArrayList<>(servers));
       this.attributes = checkNotNull(attributes, "attributes");
       this.serviceConfig = serviceConfig;
@@ -477,7 +478,7 @@ public Attributes getAttributes() {
      * @since 1.21.0
      */
     @Nullable
-    public Object getServiceConfig() {
+    public ConfigOrError getServiceConfig() {
       return serviceConfig;
     }
 
@@ -515,7 +516,7 @@ public static final class Builder {
       private List<EquivalentAddressGroup> servers = Collections.emptyList();
       private Attributes attributes = Attributes.EMPTY;
       @Nullable
-      private Object serviceConfig;
+      private ConfigOrError serviceConfig;
       //  Make sure to update #toBuilder above!
 
       Builder() {}
@@ -547,7 +548,7 @@ public Builder setAttributes(Attributes attributes) {
        *
        * @since 1.21.0
        */
-      public Builder setServiceConfig(@Nullable Object serviceConfig) {
+      public Builder setServiceConfig(@Nullable ConfigOrError serviceConfig) {
         this.serviceConfig = serviceConfig;
         return this;
       }