add sendRequest to VMIsolateRef

lib/src/isolate.dart

Index: lib/src/isolate.dart
diff --git a/lib/src/isolate.dart b/lib/src/isolate.dart
index d9363daa37947af26664dde7e475026e8286fba8..1d4792ff9f93bce77119c7e818dc3f6e1dc97c0a 100644
--- a/lib/src/isolate.dart
+++ b/lib/src/isolate.dart
@@ -19,6 +19,7 @@ import 'sentinel.dart';
 import 'stack.dart';
 import 'stream_manager.dart';
 import 'utils.dart';
+import 'extension.dart';
 
 VMIsolateRef newVMIsolateRef(rpc.Peer peer, StreamManager streams, Map json) {
   if (json == null) return null;
@@ -86,6 +87,11 @@ class VMIsolateRef {
   Stream<List<int>> get stderr => _stderr;
   Stream<List<int>> _stderr;
 
+  /// A broadcast stream that emits the name of VM service extensions
+  Stream<VMServiceExtension> get onServiceExtensionAdded =>
+      _onServiceExtensionAdded;
+  Stream<VMServiceExtension> _onServiceExtensionAdded;
+
   /// A future that fires when the isolate exits.
   ///
   /// If the isolate has already exited, this will complete immediately.
@@ -126,6 +132,11 @@ class VMIsolateRef {
       sink.add(new VMIsolateRef._(_scope, json["isolate"]));
     });
 
+    _onServiceExtensionAdded = _transform(_scope.streams.isolate, (json, sink) {
+      if (json["kind"] != "ServiceExtensionAdded") return;
+      sink.add(newVMServiceExtension(json["extensionRPC"]));
+    });
+
     _onPauseOrResume = _transform(_scope.streams.debug, (json, sink) {
       var event = newVMPauseEvent(_scope, json);
       if (event != null) sink.add(event);
@@ -264,6 +275,22 @@ class VMIsolateRef {
     }
   }
 
+  /// Makes a raw RPC to a VM service extension registered in this isolate
+  /// corresponding to the ID [number].
+  ///
+  /// [method] must correspond to a VM service extension installed on the VM
+  /// isolate and it must begin with prefix "ext.".
+  ///
+  /// [params] are passed to the extension handler and must be serializable to
+  /// a JSON string.
+  Future<Object> invokeExtension(String method, [Map<String, String> params]) {
+    if (!method.startsWith('ext.')) {
+      throw new ArgumentError.value(method, 'method',
+          'must begin with "ext." prefix');
+    }
+    return _scope.sendRequest(method, params);
+  }
+
   bool operator ==(other) => other is VMIsolateRef &&
       other._scope.isolateId == _scope.isolateId;
 
@@ -365,4 +392,4 @@ class VMStep {
   const VMStep._(this._value);
 
   String toString() => _value;
-}
+}