Fuchsia: Build standalone VM. Make it run "Hello, World!".

runtime/bin/vmservice/vmservice_io.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library vmservice_io;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:isolate';
 import 'dart:_vmservice';
 
 part 'loader.dart';
 part 'server.dart';
 
 // The TCP ip/port that the HTTP server listens on.
 int _port;
 String _ip;
 // Should the HTTP server auto start?
 bool _autoStart;
 // Should the HTTP server run in devmode?
 bool _originCheckDisabled;
-bool _isWindows = false;
+bool _hasSignals = true;

[Cutch, 2016/07/21 20:24:51]

This change is likely to break other embedders who set this flag from C++ code.

[zra, 2016/07/22 17:47:20]

Restored _isWindows. Added _isFuchsia.

 var _signalWatch;
 var _signalSubscription;
 
 // HTTP server.
 Server server;
 Future<Server> serverFuture;
 
 _lazyServerBoot() {
   if (server != null) {
     return;
@@ skipping 135 matching lines @@
 }
 
 Timer _registerSignalHandlerTimer;
 
 _registerSignalHandler() {
   _registerSignalHandlerTimer = null;
   if (_signalWatch == null) {
     // Cannot register for signals.
     return;
   }
-  if (_isWindows) {
-    // Cannot register for signals on Windows.
+  if (!_hasSignals) {
+    // Cannot register for signals on Windows or Fuchsia.
     return;
   }
   _signalSubscription = _signalWatch(ProcessSignal.SIGQUIT).listen(_onSignal);
 }
 
 main() {
   // Set embedder hooks.
   VMServiceEmbedderHooks.cleanup = cleanupCallback;
   VMServiceEmbedderHooks.createTempDir = createTempDirCallback;
   VMServiceEmbedderHooks.deleteDir = deleteDirCallback;
@@ skipping 11 matching lines @@
     Timer.run(() {});
   }
   scriptLoadPort.handler = _processLoadRequest;
   // Register signal handler after a small delay to avoid stalling main
   // isolate startup.
   _registerSignalHandlerTimer = new Timer(shortDelay, _registerSignalHandler);
   return scriptLoadPort;
 }
 
 _shutdown() native "VMServiceIO_Shutdown";