Remove StreamSink(replaced by EventSink) and make IOSink extend EventSink.

tests/standalone/io/file_test.dart

 // Copyright (c) 2013, 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.
 //
 // Dart test program for testing file I/O.
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
@@ skipping 74 matching lines @@
       (d) {
         buffer.addAll(d);
       },
       onDone: () {
         Expect.equals(42, buffer.length);
         // Write the contents of the file just read into another file.
         String outFilename =
             tempDirectory.path + "/out_read_write_stream";
         var file2 = new File(outFilename);
         var output = file2.openWrite();
-        output.writeBytes(buffer);
+        output.add(buffer);
         output.close();
         output.done.then((_) {
           // Now read the contents of the file just written.
           List<int> buffer2 = new List<int>();
           new File(outFilename).openRead().listen(
               (d) {
                 buffer2.addAll(d);
               },
               onDone: () {
                 Expect.equals(42, buffer2.length);
@@ skipping 17 matching lines @@
 
     // Create the test data - arbitrary binary data.
     List<int> buffer = new List<int>(100000);
     for (var i = 0; i < buffer.length; ++i) {
       buffer[i] = i % 256;
     }
     String filename =
         tempDirectory.path + "/out_read_write_stream_large_file";
     File file = new File(filename);
     IOSink output = file.openWrite();
-    output.writeBytes(buffer);
-    output.writeBytes(buffer);
+    output.add(buffer);
+    output.add(buffer);
     output.close();
     output.done.then((_) {
       Stream input = file.openRead();
       int position = 0;
       final int expectedLength = 200000;
       // Start an independent asynchronous check on the length.
       asyncTestStarted();
       file.length().then((len) {
         Expect.equals(expectedLength, len);
         asyncTestDone('testReadWriteStreamLargeFile: length check');
@@ skipping 193 matching lines @@
     file.deleteSync();
   }
 
   static void testOutputStreamWriteAppend() {
     String content = "foobar";
     String filename = tempDirectory.path + "/outstream_write_append";
     File file = new File(filename);
     file.createSync();
     List<int> buffer = content.codeUnits;
     var output = file.openWrite();
-    output.writeBytes(buffer);
+    output.add(buffer);
     output.close();
     output.done.then((_) {
       File file2 = new File(filename);
       var appendingOutput = file2.openWrite(mode: FileMode.APPEND);
-      appendingOutput.writeBytes(buffer);
+      appendingOutput.add(buffer);
       appendingOutput.close();
       appendingOutput.done.then((_) {
         File file3 = new File(filename);
         file3.open(mode: FileMode.READ).then((RandomAccessFile openedFile) {
           openedFile.length().then((int length) {
             Expect.equals(content.length * 2, length);
             openedFile.close().then((ignore) {
               file3.delete().then((ignore) {
                 asyncTestDone("testOutputStreamWriteAppend");
               });
@@ skipping 395 matching lines @@
 
   // Tests stream exception handling after file was closed.
   static void testCloseExceptionStream() {
     asyncTestStarted();
     List<int> buffer = new List<int>(42);
     File file =
         new File(tempDirectory.path + "/out_close_exception_stream");
     file.createSync();
     var output = file.openWrite();
     output.close();
-    Expect.throws(() => output.writeBytes(buffer));
+    Expect.throws(() => output.add(buffer));
     output.done.then((_) {
       file.deleteSync();
       asyncTestDone("testCloseExceptionStream");
     });
   }
 
   // Tests buffer out of bounds exception.
   static void testBufferOutOfBoundsException() {
     bool exceptionCaught = false;
     bool wrongExceptionCaught = false;
@@ skipping 457 matching lines @@
       testDirectorySync();
       testWriteStringUtf8();
       testWriteStringUtf8Sync();
     });
   }
 }
 
 main() {
   FileTest.testMain();
 }