Port async file operations to be using native ports instead or an isolate

tests/standalone/src/FileTest.dart

Index: tests/standalone/src/FileTest.dart
diff --git a/tests/standalone/src/FileTest.dart b/tests/standalone/src/FileTest.dart
index c0519eae3a21b46f86546a22483f2e084f1f5f1a..0803b08dab4a91aa72cf792db1ed271c6801419e 100644
--- a/tests/standalone/src/FileTest.dart
+++ b/tests/standalone/src/FileTest.dart
@@ -423,13 +423,10 @@ class FileTest {
         x = 12345678901234567890123456789012345678901234567890;
         y = 12345678901234567890123456789012345678901234568153;
         openedFile.writeList([y - x], 0, 1);
-
+        openedFile.close();

[Mads Ager (google), 2012/02/23 08:57:44]

Why did you need to rewrite this test?

[Søren Gjesse, 2012/02/23 10:26:42]

Actually I didn't - reverted (I was testing calling close directly after write -
we should add some tests for that).

         openedFile.errorHandler = (s) {
           Expect.fail("No errors expected : $s");
         };
-        openedFile.noPendingWriteHandler = () {
-          openedFile.close();
-        };
         openedFile.closeHandler = () {
           // Check the written bytes.
           final File file2 = new File(fileName);