Make FileInputStream and FileOutputStream actually asynchronous.

tests/standalone/src/FileInputStreamTest.dart

 // Copyright (c) 2012, 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.
 // Testing file input stream, VM-only, standalone test.
 
 #import("dart:io");
 
 // Helper method to be able to run the test from the runtime
 // directory, or the top directory.
 String getFilename(String path) =>
@@ skipping 14 matching lines @@
   };
 }
 
 void testInputStreamAsync() {
   String fileName = getFilename("tests/standalone/src/readuntil_test.dat");
   // File contains "Hello Dart\nwassup!\n"
   var expected = "Hello Dart\nwassup!\n".charCodes();
   InputStream x = (new File(fileName)).openInputStreamSync();
   var byteCount = 0;
   x.dataHandler = () {
-    Expect.equals(expected[byteCount],  x.read(1)[0]);
+    Expect.equals(expected[byteCount], x.read(1)[0]);
     byteCount++;
   };
   x.closeHandler = () {
     Expect.equals(expected.length, byteCount);
   };
 }
 
 
 void testStringInputStreamAsync(String name, int length) {
   String fileName = getFilename("tests/standalone/src/$name");
@@ skipping 10 matching lines @@
       Expect.equals("Line $lineCount", line);
     }
   };
   x.closeHandler = () {
     Expect.equals(10, lineCount);
   };
 }
 
 
 void testChunkedInputStream() {
+  // Force the test to timeout if it does not finish.
+  ReceivePort done = new ReceivePort.singleShot();
+  done.receive((message, replyTo) {});
+
   String fileName = getFilename("tests/standalone/src/readuntil_test.dat");
   // File contains 19 bytes ("Hello Dart\nwassup!")
   File file = new File(fileName);
   ChunkedInputStream x = new ChunkedInputStream(file.openInputStreamSync());
   x.chunkSize = 9;
-  List<int> chunk = x.read();
-  Expect.equals(9, chunk.length);
-  x.chunkSize = 5;
-  chunk = x.read();
-  Expect.equals(5, chunk.length);
-  chunk = x.read();
-  Expect.equals(5, chunk.length);
-  chunk = x.read();
-  Expect.equals(null, chunk);
+  x.dataHandler = () {
+    List<int> chunk = x.read();
+    Expect.equals(9, chunk.length);
+    x.chunkSize = 5;
+    x.dataHandler = () {
+      chunk = x.read();
+      Expect.equals(5, chunk.length);
+      x.dataHandler = () {
+        chunk = x.read();
+        Expect.equals(5, chunk.length);
+        chunk = x.read();
+        Expect.equals(null, chunk);
+        done.toSendPort().send(null);
+      };
+    };
+  };
 }
 
 
 void testOpenInputStreamAsync() {
   // Create a port for waiting on the final result of this test.
-  ReceivePort done = new ReceivePort();
-  done.receive((message, replyTo) {
-    done.close();
-  });
+  ReceivePort done = new ReceivePort.singleShot();
+  done.receive((message, replyTo) {});
 
   // Test using the asynchronous way of opening an input stream.
   String fileName = getFilename("tests/standalone/src/readuntil_test.dat");
   File file = new File(fileName);
   file.exists();
   file.existsHandler = (exists) {
     if (exists) {
       file.openInputStream();
     } else {
       Expect.fail("Test file not found");
@@ skipping 12 matching lines @@
   testStringInputStreamSync();
   testInputStreamAsync();
   // Check the length of these files as both are text files where one
   // is without a terminating line separator which can easily be added
   // back if accidentally opened in a text editor.
   testStringInputStreamAsync("readline_test1.dat", 111);
   testStringInputStreamAsync("readline_test2.dat", 114);
   testChunkedInputStream();
   testOpenInputStreamAsync();
 }