Rename blahHandler to onBlah throughout dart:io.

tests/standalone/src/FileOutputStreamTest.dart

Index: tests/standalone/src/FileOutputStreamTest.dart
diff --git a/tests/standalone/src/FileOutputStreamTest.dart b/tests/standalone/src/FileOutputStreamTest.dart
index 95ef132d7b3157e57f3d6a3213dca9db06444bb4..4dd28f5b6e707860473956c13ca1001523dd34f2 100644
--- a/tests/standalone/src/FileOutputStreamTest.dart
+++ b/tests/standalone/src/FileOutputStreamTest.dart
@@ -23,7 +23,7 @@ void testOpenOutputStreamSync() {
   OutputStream x = file.openOutputStream();
   x.write([65, 66, 67]);
   x.close();
-  x.closeHandler = () {
+  x.onClose = () {
     file.deleteSync();
     done.toSendPort().send("done");
   };
@@ -37,26 +37,26 @@ void testOutputStreamNoPendingWrite() {
   ReceivePort done = new ReceivePort();
   done.receive((message, replyTo) {
     tempDirectory.delete();
-    tempDirectory.deleteHandler = () {
+    tempDirectory.onDelete = () {
       done.close();
     };
   });
 
   tempDirectory.createTemp();
-  tempDirectory.createTempHandler = () {
+  tempDirectory.onCreateTemp = () {
     String fileName = "${tempDirectory.path}/test";
     File file = new File(fileName);
     file.create();
-    file.createHandler = () {
+    file.onCreate = () {
       OutputStream stream = file.openOutputStream();
       final total = 100;
       var count = 0;
-      stream.noPendingWriteHandler = () {
+      stream.onNoPendingWrite = () {
         stream.write([count++]);
         if (count == total) {
           stream.close();
         }
-        stream.closeHandler = () {
+        stream.onClose = () {
           List buffer = new List<int>(total);
           File fileSync = new File(fileName);
           var openedFile = fileSync.openSync();