add sendRequest to VMIsolateRef

lib/src/extension.dart

+// Copyright (c) 2016, 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.
+
+import 'scope.dart';
+
+VMServiceExtension newVMServiceExtension(String method) {
+  assert(method != null);
+  return new VMServiceExtension._(method);
+}
+
+/// Represents a VM service extension registered in an isolate.
+///
+/// Extensions are registered using `registerExtension` from the
+/// `dart:developer` package.
+class VMServiceExtension {

[nweiz, 2016/02/16 22:03:20]

Since Isolate.extensionRPCs is a set of strings, I think we can reasonably
assume that extensions won't have additional metadata added in the future. As
such, I think VMIsolateRef.onServiceExtensionAdded can safely emit strings
rather than custom objects.

[yjbanov, 2016/02/16 22:31:49]

Done.

+  /// RPC method name under which the extension is registered.
+  final String method;
+
+  VMServiceExtension._(this.method);
+}