core: MutableHandlerRegistry#addService with BindableService arg

core/src/main/java/io/grpc/util/MutableHandlerRegistry.java

@@ -31,6 +31,7 @@
 
 package io.grpc.util;
 
+import io.grpc.BindableService;
 import io.grpc.ExperimentalApi;
 import io.grpc.HandlerRegistry;
 import io.grpc.MethodDescriptor;
@@ -55,11 +56,28 @@ public final class MutableHandlerRegistry extends HandlerRegistry {
   private final ConcurrentMap<String, ServerServiceDefinition> services
       = new ConcurrentHashMap<String, ServerServiceDefinition>();
 
+  /**
+   * Registers a service.
+   *
+   * @return the previously registered service with the same service descriptor name if exists,
+   *         otherwise {@code null}.
+   */
   @Nullable
   public ServerServiceDefinition addService(ServerServiceDefinition service) {
     return services.put(service.getServiceDescriptor().getName(), service);
   }
 
+  /**
+   * Registers a service.
+   *
+   * @return the previously registered service with the same service descriptor name if exists,
+   *         otherwise {@code null}.
+   */
+  @Nullable
+  public ServerServiceDefinition addService(BindableService bindableService) {
+    return addService(bindableService.bindService());
+  }
+
   public boolean removeService(ServerServiceDefinition service) {
     return services.remove(service.getServiceDescriptor().getName(), service);
   }

core/src/test/java/io/grpc/util/MutableHandlerRegistryTest.java

@@ -38,6 +38,7 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
+import io.grpc.BindableService;
 import io.grpc.MethodDescriptor.Marshaller;
 import io.grpc.MethodDescriptor.MethodType;
 import io.grpc.MethodDescriptor;
@@ -129,6 +130,22 @@ public class MutableHandlerRegistryTest {
     assertNull(registry.lookupMethod("completely/random"));
   }
 
+  @Test
+  public void simpleLookupWithBindable() {
+    BindableService bindableService =
+        new BindableService() {
+          @Override
+          public ServerServiceDefinition bindService() {
+            return basicServiceDefinition;
+          }
+        };
+
+    assertNull(registry.addService(bindableService));
+
+    ServerMethodDefinition<?, ?> method = registry.lookupMethod("basic/flow");
+    assertSame(flowMethodDefinition, method);
+  }
+
   @Test
   public void multiServiceLookup() {
     assertNull(registry.addService(basicServiceDefinition));