Cleanup vm_service library loading.

runtime/bin/vmservice/vmservice.dart

Index: runtime/bin/vmservice/vmservice.dart
diff --git a/runtime/bin/vmservice/vmservice.dart b/runtime/bin/vmservice/vmservice.dart
index f1f8995a7396b1d61ad395f97d9c59bdb89b30d4..ad6613fd72d8f17e46531622604d9a982ae49632 100644
--- a/runtime/bin/vmservice/vmservice.dart
+++ b/runtime/bin/vmservice/vmservice.dart
@@ -6,15 +6,19 @@ library vmservice;
 
 import 'dart:async';
 import 'dart:json' as JSON;
-// TODO(11927): Factor 'dart:io' dependency into separate library.
-import 'dart:io';
 import 'dart:isolate';
 import 'dart:typed_data';
 import 'dart:utf' as UTF;
 
+part 'constants.dart';
+part 'resources.dart';
+part 'running_isolate.dart';
+part 'running_isolates.dart';
+part 'service_request.dart';
+part 'service_request_router.dart';
 
-class VmService {
-  static VmService _instance;
+class VMService {
+  static VMService _instance;
   RunningIsolates runningIsolates = new RunningIsolates();
 
   void controlMessageHandler(int code, SendPort sp) {
@@ -34,13 +38,13 @@ class VmService {
     }
   }
 
-  VmService._internal() {
+  VMService._internal() {
     port.receive(messageHandler);
   }
 
-  factory VmService() {
-    if (VmService._instance == null) {
-      VmService._instance = new VmService._internal();
+  factory VMService() {
+    if (VMService._instance == null) {
+      VMService._instance = new VMService._internal();
     }
     return _instance;
   }