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

tests/standalone/io/http_server_response_test.dart

Index: tests/standalone/io/http_server_response_test.dart
diff --git a/tests/standalone/io/http_server_response_test.dart b/tests/standalone/io/http_server_response_test.dart
index 946f2660a117010f6d53af480c09c553b97d88bd..51ad60d8ae07da25e73e11cdf89034950a62ec2e 100644
--- a/tests/standalone/io/http_server_response_test.dart
+++ b/tests/standalone/io/http_server_response_test.dart
@@ -88,7 +88,7 @@ void testResponseAddStream() {
 void testBadResponseAdd() {
   testServerRequest((server, request) {
     request.response.contentLength = 0;
-    request.response.writeBytes([0]);
+    request.response.add([0]);
     request.response.close();
     request.response.done.catchError((error) {
       server.close();
@@ -97,8 +97,8 @@ void testBadResponseAdd() {
 
   testServerRequest((server, request) {
     request.response.contentLength = 5;
-    request.response.writeBytes([0, 0, 0]);
-    request.response.writeBytes([0, 0, 0]);
+    request.response.add([0, 0, 0]);
+    request.response.add([0, 0, 0]);
     request.response.close();
     request.response.done.catchError((error) {
       server.close();
@@ -107,9 +107,9 @@ void testBadResponseAdd() {
 
   testServerRequest((server, request) {
     request.response.contentLength = 0;
-    request.response.writeBytes(new Uint8List(64 * 1024));
-    request.response.writeBytes(new Uint8List(64 * 1024));
-    request.response.writeBytes(new Uint8List(64 * 1024));
+    request.response.add(new Uint8List(64 * 1024));
+    request.response.add(new Uint8List(64 * 1024));
+    request.response.add(new Uint8List(64 * 1024));
     request.response.close();
     request.response.done.catchError((error) {
       server.close();
@@ -128,7 +128,7 @@ void testBadResponseClose() {
 
   testServerRequest((server, request) {
     request.response.contentLength = 5;
-    request.response.writeBytes([0]);
+    request.response.add([0]);
     request.response.close();
     request.response.done.catchError((error) {
       server.close();