Dart: Use a RawReceivePort to receive events for Mojo handles.

mojo/public/dart/mojo/lib/src/drain_data.dart

Index: mojo/public/dart/mojo/lib/src/drain_data.dart
diff --git a/mojo/public/dart/mojo/lib/src/drain_data.dart b/mojo/public/dart/mojo/lib/src/drain_data.dart
index b5929e567a3191f1582a32bcc011bb28a9a43549..dc630bfbdc7c1a2fc73b72023bcebd4af8a2fe6a 100644
--- a/mojo/public/dart/mojo/lib/src/drain_data.dart
+++ b/mojo/public/dart/mojo/lib/src/drain_data.dart
@@ -6,19 +6,18 @@ part of core;
 
 class DataPipeDrainer {
   MojoDataPipeConsumer _consumer;
-  MojoEventStream _eventStream;
+  MojoEventSubscription _eventSubscription;
   List<ByteData> _dataList;
   int _dataSize;
 
   DataPipeDrainer(this._consumer) {
-    _eventStream = new MojoEventStream(_consumer.handle);
+    _eventSubscription = new MojoEventSubscription(_consumer.handle);
     _dataList = new List();
     _dataSize = 0;
   }
 
-  ByteData _copy(ByteData byteData) =>
-      new ByteData.view(
-          new Uint8List.fromList(byteData.buffer.asUint8List()).buffer);
+  ByteData _copy(ByteData byteData) => new ByteData.view(
+      new Uint8List.fromList(byteData.buffer.asUint8List()).buffer);
 
   MojoResult _doRead() {
     ByteData thisRead = _consumer.beginRead();
@@ -34,8 +33,9 @@ class DataPipeDrainer {
     var data = new ByteData(_dataSize);
     int end = 0;
     for (var chunk in _dataList) {
-      data.buffer.asUint8List().setRange(
-          end, end + chunk.lengthInBytes, chunk.buffer.asUint8List());
+      data.buffer
+          .asUint8List()
+          .setRange(end, end + chunk.lengthInBytes, chunk.buffer.asUint8List());
       end += chunk.lengthInBytes;
     }
     return data;
@@ -43,20 +43,20 @@ class DataPipeDrainer {
 
   Future<ByteData> drain() {
     var completer = new Completer();
-    _eventStream.listen((List<int> event) {
+    _eventSubscription.subscribe((List<int> event) {
       var mojoSignals = new MojoHandleSignals(event[1]);
       if (mojoSignals.isReadable) {
         var result = _doRead();
         if (!result.isOk) {
-          _eventStream.close();
-          _eventStream = null;
+          _eventSubscription.close();
+          _eventSubscription = null;
           completer.complete(_concatData());
         } else {
-          _eventStream.enableReadEvents();
+          _eventSubscription.enableReadEvents();
         }
       } else if (mojoSignals.isPeerClosed) {
-        _eventStream.close();
-        _eventStream = null;
+        _eventSubscription.close();
+        _eventSubscription = null;
         completer.complete(_concatData());
       } else {
         throw 'Unexpected handle event: $mojoSignals';